Mathematics Topics

0.017453292519943295
The number of radians in 1 degree.
0.301029995664
log10(2)
0.434294481903
log10(e)
0.477121254720
log10(3)
0.497149872694
log10(π)
0.57721566490
Euler′s constant.
0.693147180560
loge(2)
0.915965594177219015
Catalans constant.
1.098612288668
loge(3)
1.414213562
Square root of 2.
1.9021605824
Brun′s constant, the sum of the reciprocals of all twin primes.
2.302585092994
loge(10)
2.71828
The base of natural (Napierian) logarithms
3.14159265
Pi is the number of times the diameter of a circle can be divided into the circumference.
57.29577951308232
The number of degrees in 1 radian.
Ab Initio
Latin meaning "from first principles".
Abacus
The uppermost part of a colurnn capital or pilaster, on which the architrave rests. Also, a bead frame used as an arithmetic calculating aid.
Abelian Group
A mathematical group of transformations with the property that the end result of a series of transformations does not depend on the order in which they are performed.
Abscissa
The x coordinate on an (x, y) graph.
Absolute Value
The positive value for a real number, disregarding the sign.
Abundant Number
A positive integer that is smaller than the sum of its proper divisors.
Addition of Ordinates
A graphing technique where two or more functions are independently plotted on the same graph, then their y-coordinates are added together at each point to form the new graph.
Affine Cipher
Affine ciphers use linear functions to scramble the letters of secret messages.
Algebra
First major treatise written by Al-Khawarizmi in AD 810.
Algorithm
A logical sequence of instructions that explain how to accomplish a task. It must explain exactly how to go from one step to the next and have a finite amount of steps.
Align
To adjust or set to a line or centre.
Alpha
The first letter of the Greek alphabet.
Alphametic
A cryptarithm in which the letters, which represent distinct digits, form related words or meaningful phrases.
Altitude of a Conic Solid
The length of a segment whose endpoints are the vertex and a point on the plane of the base that is perpendicular to the plane of the base.
Altitude of a Cylindric Solid
The distance between the planes of the bases.
Altitude of a Trapezoid
The distance between the bases of a trapeziod.
Amicable Numbers
Two numbers are said to be amicable if each is equal to the sum of the proper divisors of the other.
Analysis
Lists all Analysis topics in the Encyclopaedia
Angular Frequency
The frequency of a steady recurring phenomenum in radians per second.
Annulus
The region enclosed by two concentric circles.
Apodize
To apodize is to remove or smooth a sharp discontinuity in a mathematical function, an electrical signal or a mechanical structure.
Arbitrary Unit
A unit that is not part of the standardized metric or other system.
Arc Length
The distance between the endpoints of an arc along the path of the circle.
Arccos
The inverse of cosine. Note that arccos(A)=cos-1(x).
Arccot
The inverse of cotangent. Note that arccot(A)=cot-1(x).
Arccsc
The inverse of cosecant. Note that arccsc(A)=csc-1(x).
Archimedes Constant
More commonly known as Pi.
Arcminute
Defined as 1/60 of a degree.
Arcsec
The inverse of secant. Note that arcsec(A)=sec-1(x).
Arcsecond
Defined as 1/360 of a degree.
arcsin
The inverse of sine. Note that arcsin(A)=sin-1(x).
Arctan
The inverse of tangent. Note that arctan(A)=tan-1(x).
Arithmetic
The type of mathematics that studies how to solve problems involving numbers, but not variables.
Arithmetic Coding
Arithmetic coding removes this restriction by representing messages as intervals of the real numbers between 0 and 1.
Arithmetic Operators
Symbols and signs used in mathematics.
Ascendent
A vector with magnitude equal to the maximum spatial rate of change of that function at a given point at a given time and directed toward increasing values of the function along the line of maximum change.
Asn
The inverse of sine. Note that asn(A)=sin-1(x).
Associative Property
When adding or multiplying three numbers, it doesn′t matter if the first two or the last two numbers are added or multiplied first.
Attribute
An identifiable property of an object, set, or event that is subject to being measured.
Automorphism
An isomorphism from a set onto itslef.
Autospectrum
A spectrum with the coefficients of the components expressed as the square of the magnitudes
Average
A statistic calculated by summing a set of data values and dividing by the number of values.
Average Expected Payoff
An estimate of the amount that will be gained in a game of chance, calculated by multiplying the probability of winning by the number of points won each time.
Averaging
In any process it is often necessary to average a number of measurements to gain any confidence in the measured value.
Axiom
A statement assumed to be true without the need for proof.
Axis
The line, real or imaginary, passing through the centre of an object about which it could rotate; a point of reference.
Axis of Symmetry
A line that passes through a graph or figure such that one side of the figure is an exact mirror image of the other.
Azimuth Angle
Azimuth measured from 0° at the north or south reference direction clockwise or counterclockwise through 90° or 180°.
Ball
A sphere together with its interior.
Bar Chart
A strong graphical representation of data.
Base
Substance which gives off hydroxide ions (OH-) in solution. In the expression xy, x is called the base and y is the exponent.
Basis Function
A mathematical function that can be used to build a description of wavefunctions for electrons in atoms or molecules.
Basis Set
A set of mathematical functions that are combined to approximate the wavefunctions for electrons in atoms and molecules.
Bayes Rule
A rule for finding conditional probability.
Behavioural Envelope
Envelope of response versus frequency.
Bell Curve
A continuous probability distribution that often gives a good description of data that cluster around the mean.
Beta
A letter of the Greek alphabet.
Bijection
A one-to-one onto transformation.
Bimodal
In the home entertainment context, pertaining to presentations involving the visual and auditory sensory modalities.
Binary
Pertaining to a characteristic that involves the selection, choice, or condition in which there are only two possibilities.
Binary Coded Decimal
A number system where each decimal digit is separately represented by a 4-bit binary code.
Binary Coded Digit
A digit of any number system that is represented as a fixed number of binary digits
Binary Notation
In order to understand how a number in binary notation is constructed, the decimal notation is first discussed.
Binary Number
A number written to base 2.
Binary Point
The radix point that separates powers of two and fractional powers of two in a binary number.
Binomial Coefficient
The coefficients of x in the expansion of (x+1)n.
Bisect
Bisect means to cut something in half. For example, to bisect an angle, you would draw a line through the vertex of the angle such that the two angles created are equivalent in measure.
Black Box
A unit whose output is a specified function of the input, but for which the method of converting input to output is not necessarily specified.
Boolean
Pertaining to the operations of formal logic.
Bore
The interior diameter of a cylinder.
Boundary Element Method
A mathematical formulation used to predict acoustic parameters such as pressure and power. This technique may be applied to interior and exterior acoustic problems.
Box
A surface made up of rectangles; a rectangular parallelpided.
Box Plot
A graphic method that shows the distribution of a set of data by using the median, quartiles, and the extremes of the data set.
Braces
The symbols { and } used for grouping or to represent a set.
Brun′s Constant
The sum of the reciprocals of all twin primes.
Cahen Constant
Defined as an infinite series of unit fractions, with alternating signs.
Calculator
A machine for performing arithemtical calculations.
Caliban Puzzle
A logic puzzle in which one is asked to infer one or more facts from a set of given facts.
Canonical Form
In a mathematical context this term is taken to mean a generic or basic representation.
Cardinal Number
A number that indicates the quantity but not the order of things.
Cardioid
The curve described by a point on a circle of radius r as it rolls on the outside of another circle of radius r.
Cartesian Coordinates
Coordinates where the position of a point is described by the distance it is from 2 lines in 2 dimensional space or from 3 planes in 3 dimensional space.
Cartesian Plane
A coordinate plane.
Catalans Constant
= 0.915965594177219015
Ceiling Function
The ceiling function of x is the smallest integer greater than or equal to x.
Centillion
A number equal to 10303.
Central Limit Theorem
A random sample of observations from any distribution with a finite mean and a finite variance, the average will tend to follow a normal distribution for large samples.
Central Tendencies
A number which in some way conveys the "centre" or "middle" of a set of data. The most frequently used measures are the mean and the median.
Centre
A point or axis around which anything revolves or rotates.
Centroid
The centre of mass of a figure.
Cepstrum
A cepstrum is a time history defined as the power spectrum of the logarithm of the Power spectrum.
Chaos
The breakdown of predictability, or a state of disorder.
Cipher
Codes for writing secret messages.
Circular Cone
A cone whose base is a circle.
Circumcentre
The circumcentre of a triangle is the center of the circumscribed circle.
Circumcircle
The circle circumscribed about a figure.
Circumference
The perimeter of a circle.
Class Interval
The non-overlapping intervals of a histogram.
Closed Interval
An interval that includes it′s endpoints.
Coefficient
A coefficient is a constant multiplicative factor of a certain object.
Colinear
In the same line.
Collinear
Points are said to be collinear if they all lie on the same line.
Combinations
A combination is the set itself without reference to order.
Commutative
Describes an operator that gives the same result irrespective of the order of arguments.
Complement
The complement of a subset of a given set is the collection of all elements of the set that are not elements of the subset.
Complementary Probability
Considering probabilites in decimal form, the sum of two probabilites equal to one.
Complementary Rules
Rules in Boolean Algebra derived from the combination of a single variable with the inverse of itself.
Complex Conjugate
A complex number whose imaginary part is the negative of that of a given complex number, their real parts being equal.
Complex Numbers
A complex number consists of a real and imaginary part.
Complex Numbers, Exponential Form
Exponential expression of complex numbers.
Complex Numbers, Polar Form
Complex numbers written in polar form.
Composite Number
A natural number that is not prime.
Compund Event
Two or more events that happen simultaneously.
Compute
To solve problems that use numbers.
Concave
Curved from the inside.
Concave Up
A curve is "concave up" when it is a concave shape, meaning curved like the inside of a bowl, with the two ends of the curve pointing up.
Concurrent
Pertaining to the occurrence of two or more events or activities within the same specified interval of time.
Conditional Probability
The probability of an event occurring given that another event also occurs.
Cone
A three-dimensional solid that rises to a single point at the top.
Congruent
Equilateral, equal, exactly the same size and shape.
Congruent Figures
Two geometric figures that are identical in size and shape.
Conic Section
The cross section of a right circular cone cut by a plane.
Conjecture
A statement that may seem to be true, but has yet to be proven.
Conjugation
The operation of replacing i by -i in a complex number.
Consecutive Sides
Sides of a polygon that share an endpoint.
Consecutive Vertices
Endpoints of a single side of a polygon.
Consistent Linear System
A system of linear equations is consistent if it has at least one solution.
Constant
A quantity that does not change. This quantity may be a number or a variable.
Constant Functions
Functions that stay the same no matter what the variable does are called constant functions.
Continuous Graph
In a graph, a continuous line with no breaks in it forms a continuous graph.
Contour
The outline of an object.
Contraction
A reduction in size.
Control Chart
A chart used to determine whether the distribution of data values generated by a process is stable over time.
Control Group
The subjects in a controlled experiment who do not receive the treatment.
Convex
The curved surface of a cylinder, as a sphere when viewed from without.
Coordinate Plane
A plane with a point selected as an origin, some length selected as a unit of distance, and two perpendicular lines that intersect at the origin, with positive and negative direction selected on each line.
Coordinates
Numbers that specify the position of a point or the position or orientation of a geometric object.
Coplanar
A set of points or lines that are all on a common plane.
Coprime
Integers m and n are coprime if the greatest common divisor of m and n is 1.
Corollary to a Theorem
A corollary is a proposition that follows with little or no proof from one other theorem or definition.
Correlation Coefficient
A numerical value, between +1 and -1, that identifies the strength of the linear relationship between variables.
Cos
Trigonometric function.
Cot
Trigonometric function.
Covariance
A measure of the joint variability of a pair of numeric variables.
Cross Correlation
The cross-correlation function gives a measure of the extent to which two signals correlate with each other as a function of the time displacement between them.
Cross Spectrum
The cross spectrum Fxy(f) of fx(t) and fy(t) is the forward Fourier Transform of the cross correlation function Rxy(T). The cross spectrum is in general complex.
Cryptarithm
A number puzzle.
Cryptography
Field of mathematics and computer science concerned with information security and related issues, particularly encryption and authentication.
csc
Abbreviation of the trigonometric function cosecant.
Cumulative Frequency
The number of observations falling in a given class in a frequency table, plus all observations falling in earlier classes.
Cumulative Probability
The probability that a random variable will be less than or equal to a specified value.
Cumulative Relative Frequency
The number of observations falling in a given class in a frequency table, plus all observations falling in earlier classes, divided by the total number of observations.
Curvature
Departure from flatness of a surface. Defined as the reciprocal of the radius of curvature.
Curve Sketching
When sketching a curve there are a number of general features to look for.
Cycloid
The curve described by a point on a circle as it rolls along a line.
Cylinder
A right angle circular cylinder.
Deciles
The 10th, 20th, 30th, ...90th percentile points.
Decillion
A number equal to 1033.
Decimal
Pertaining to the number representation system with a radix of ten.
Decimal Number
A number written to the base 10.
Decimal Point
The period in a decimal number separating the integer part from the fractional part.
Deduction
A conclusion derived by reasoning.
Defective Matrix
A matrix A is defective if A has an eigenvalue whose geometric multiplicity is less than its algebraic multiplicity.
Deficient Number
A positive integer that is larger than the sum of its proper divisors.
Del Operator
The del or grad operation means to take the derivative with respect to distance, in 3 dimensions.
de Moivre
Named after the analyst and probability theorist Abraham de Moivre.
Dense Line
The line that contains the shortest path between two points.
Density Function
A mathematical function used to determine probabilities for a continuous random variable.
Dependent Variable
The dependent or response variable is the variable whose behaviour is to be measured as a result of an experiment.
DFT
The Discrete Fourier Transform, the digital version of the fourier transform.
Diagonal Matrix
A diagonal matrix is an n x n matrix with every off diagonal element equal to zero.
Diameter
The longest chord of a figure. In a circle, a diameter is a chord that passes through the centre of the circle.
Digimetic
A cryptarithm in which digits represent other digits.
Digit
In the decimal system, one of the numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
Dimension
The indication of how far something extends in space.
Diophantine Equation
An equation which is required to be solved by integers.
Dirac Delta Function
The limiting case of a pulse with unit area that is infinitely short and at the same time infinitely high.
Direct Measurement
A process of obtaining the measurement of some entity by reading a measuring tool, such as a ruler for length, a scale for weight, or a protractor for angle size.
Direct Proportion
Two variables are said to be in a direct proportion if the proportions of corresponding pairs of values are always equal.
Direction
The way a number goes - positive or negative.
Disc
A circle together with its interior.
Discontinuity
A break in sequence or continuity of anything.
Discontinuous Graph
A line in a graph that is interrupted, or has breaks in it forms a discontinuous graph.
Discrete
A type of random variable which may take on only a limited set of values, such as 1,2,3,...,10.
Disjoint Events
Two events are disjoint if they can't both happen at the same time.
Distance Between Two Points
The straight line distance between two points in cartesian coordinates.
Distributive Law
States that if a group of terms connected by like operators contains the same variable, the variable may be removed from the terms and associated with them by the appropriate sign of operation.
Divergence
The divergence operation is performed on a vector and produces a scalar.
Dividend
A number or quantity that is to be divided by another number or quantity.
Divisor
A number or quantity that is to be divided into another number or quantity.
Domain
The set of all allowable inputs for a function.
Domain of the Function
The set of numbers x for which f(x) is defined.
Dot
A description of a point in which the point has a definite size.
Duodecimal Number System
The system of numeration with base 12.
e
Natural base of logarithms e=2.718281...
Eigenvalue
Possible values for a parameter of an equation for which the solutions will be compatible with the boundary conditions.
Element
A member of or an object in a set.
Elementary Matrix
A matrix that is obtained by performing an elementary row operation on an identity matrix.
Ellipse
A plane through a right angle cone.
Empty Set
The set with no elements in it.
End Point Convention
In histograms, you need to decide where to count values that are on the exact boundary between two intervals: either in the left or in the right interval.
Enumerable Set
A countable set.
Epicycloid
The curve described by a point on a circle of radius b as it rolls on the outside of a circle of radius a.
Equality
The relationship between two quantities that have the same value or values.
Equally Likely
In probability, when there are the same chances for more than one event to happen, the events are equally likely to occur.
Equidistant
The same distance from something.
Equilateral
Equal in length.
Equivalent Linear Systems
Two systems of linear equations in n unknowns are equivalent if they have the same set of solutions.
Eratosthenes
Around 230BC developed a method for finding all prime numbers.
Errors
No measurement is exact, they all contain some degree of errors.
Escapees
Values for C in the Julia Set or Mandelbrot set where at each iteration the resulting value grows larger and larger, approaching infinity.
Estimate
An indication of the value of an unknown quantity based on observed data.
Estimation
The process by which sample data are used to indicate the value of an unknown quantity in a population.
Estimator
Any quantity calculated from the sample data which is used to give information about an unknown quantity in the population.
Euclid
Greek mathematician.
Euclidean Algorithm
A set of rules which when applied to two integers produces their common divisor.
Eulers Constant
γ = 0.5772156…..
Even Function
A function f(x) is called an even function if f(x)=f(-x) for all x.
Even Node
A node that has an even number of arcs.
Even Number
An integer that is divisible by 2.
Event
In probability, an event is a set of outcomes from a given experiment.
Exclusive Or
One or the other, but not both.
Expansion
An increase in size.
Experimental Probability
The chances of something happening, based on repeated testing and observing results.
Exponent
In the expression am, m is the exponent and a is the base. am is the mth power of a. If this is set equal to y (y=am) then this is called an exponential function.
Exponential Form of Complex Numbers
Exponential expression of complex numbers.
Expression
A validated series of variables, constants, and functions that can be connected by operating symbols to describe a desired computation.
Factor
Numbers or other things that get multiplied.
Factored
A polynomial has been factored or is in factored form, when it is written as a product of lower degree polynomials.
Factorial
Definition of factorial.
Famous Scientists & Engineers
Lists all the Famous Scientists & Engineers in the Encyclopaedia
Farey Sequence
The sequence obtained by arranging in numerical order all the proper fractions having denominators not greater than a given integer.
Feigendaum Constants
Two mathematical constants.
Fermat Number
The integers Fn=22n+1 are Fermat numbers.
Fermat′s Last Theorem
States that xn+yn=zn has no whole number solutions for n greater than 2.
FFT
An abbreviation of Fast Fourier Transform, an algorithm, or digital calculation routine, that efficiently calculates the discrete Fourier transform from the sampled time waveform.
Fibonacci
His book "Liber Abaci" he introduced Arabic notation for numerals and their algorithms for arithmetic.
Fibonacci Number
A member of the sequence 0, 1, 1, 2, 3, 5,... where each number is the sum of the previous two numbers.
Figurate Numbers
Polygonal numbers.
Figure
A geometric form consisting of any combination of points, lines, or planes.
Finite Group
A group containing a finite number of elements.
Floor Function
The floor function of x is the greatest integer in x, i.e. the largest integer less than or equal to x.
Four Colour Theorem
It is desired to colour a political map on a plane so that countries sharing a common boundary are coloured differently.
Fractals
Discovered by Benoit Mandelbrot in 1964.
Frequency View
An approach taken by mathematicians and scientists to determine the chances of an event happening by repeating the experiment many times and using the results to calculate the probability.
Galileo Galilei
Astronomer, mathematician and physicist he dwelt, not on the useless question, why do things happen? but, how do things happen?
Game Theory
A branch of mathematics that seeks to model decision making in conflict situations.
GCF
The Greatest Common Factor of two numbers is the largest number that divides into both numbers evenly, with no remainder. For example, the greatest common factor of 60 and 84 is 12.
Generator
The bent line-segment or figure that replaces the initiator at each iteration of a fractal.
Genetic Algorithm
A type of optimization algorithm that uses Darwinian principles to evolve a solution to a mathematical model based on survival of the fittest.
Geodesic
The arc on a surface of shortest length joining two given points.
Geodesy
The study of the shape of the Earth, e.g. its deviations from an exact sphere.
Geometric Progression
A sequence in which the ratio of each term to the preceding term is a given constant.
Geometric Sequence
A set where each element is a multiple of the previous element.
Geometric Series
A series in which the ratio of each term to the preceding term is a given constant.
Geometric Solid
The bounding surface of a 3-dimensional portion of space.
Geometry
The branch of mathematics that deals with the nature of space and the size, shape, and other properties of figures as well as the transformations that preserve these properties.
Gergonne Point
In a triangle, the lines from the vertices to the points of contact of the opposite sides with the inscribed circle meet in a point called the Gergonne point.
Given
Information assumed to be true in a proof.
Gnomon Magic Square
A 3 X 3 array in which the elements in each 2 X 2 corner have the same sum.
Golden Mean
The proportion of the division of a line so that the smaller part is to the larger part what the larger part is to the whole. This may be applied to the lengths of the sides of a rectangle.
Golden Rectangle
A rectangle whose sides are in the golden ratio.
Googol
A number equal to 10100.
Googolplex
A number equal to 10googol. Where a googol is 10100.
Graceful Graph
A graph is said to be graceful if you can number the n vertices with the integers from 1 to n and then label each edge with the difference between the numbers at the vertices, in such a way that each edge receives a different label.
Grad Operator
The del or grad operation means to take the derivative with respect to distance, in 3 dimensions.
Grade of a Slope
The pitch of a slope, and is often expressed as a percent tangent, or rise over run.
Gradient
The rate of change of a quantity.
Graph
A pictorial presentation of the relation between two or more variables.
Graph Paper
Paper that is printed with fine lines making up a regular grid.
Graph Theory
The mathematics of complicated networks.
Greater Than
An inequality that says the variable on the left is greater than the variable to the right of the inequality.
Greater than or Equal to
An inequality that says the variable on the left is greater than or equal to the variable to the right of the inequality.
Greatest Common Divisor
The greatest common factor of two numbers is the largest number that divides into both numbers evenly, with no remainder.
Greatest Common Factor
The greatest common factor of two numbers is the largest number that divides into both numbers evenly, with no remainder. For example, the greatest common factor of 60 and 84 is 12.
Greatest Lower Bound
The greatest lower bound of a set of real numbers, is the largest real number that is smaller than each of the numbers in the set.
Grid
A tesselation of congruent squares sometimes used to measure distance.
Half
One of two equal parts.
Hankel Matrix
A matrix in which all the elements are the same along any diagonal that slopes from northeast to southwest.
Harmonic Division
A line segment is divided harmonically by two points when it is divided externally and internally into the same ratio.
Heaviside Function
Also known as the unit step function.
Heaviside Oliver
An English electrical engineer who introduced Laplace transforms into electrical engineering.
Hexadecimal
Counting system based on 16.
Hexagonal Number
A number of the form n(2n-1).
Hidden Line
Broken line used to signify a line that normally would not be seen in a drawing.
Histogram
A graphical display showing the distribution of data values in a sample by dividing the range of the data into non-overlapping intervals and counting the number of values which fall into each interval.
Homeomorphism
A one-to-one continuous transformation that preserves open and closed sets.
Homogeneous Equations
A differential equation may be described as homogeneous.
Homogeneous Linear System
A system of linear equations Ax = b is homogeneous if b = 0.
Homomorphism
A function that preserve the operators associated with the specified structure.
Horizontal Line
A line whose slope is zero.
Horizontal Plane
A plane parallel to the surface of the earth.
Horn
A funnel-shaped section.
Huffman Coding
For a given character distribution, by assigning short codes to frequently occurring characters and longer codes to infrequently occurring characters, Huffman's minimum redundancy encoding minimizes the average number of bytes required to represent the characters in a text.
Hyperbola
An open curve with two branches, all points of which have a constant difference in distance from two fixed points called focuses.
Hyperbolic Spiral
The curve whose equation in polar coordinates is r*theta=a.
Hyperboloid
A geometric solid whose equation is x2/a2+y2/b2-z2/c2=1 or x2/a2+y2/b2-z2/c2=-1.
Hypotenuse
The longest side of a right triangle.
Hypothesis
A hypothesis is a proposed answer to a problem, or an explanation that accounts for a set of facts and that can be tested by further experimentation and observation.
Hypothesis Tests
Tests based on a sample of data to determine which of two different states of nature is true.
i
i denotes the imaginary number formed by square rooting negative one.
Idempotent Law
Combining a quantity with itself either by logical addition or logical multiplication will result in a logical sum or product that is the equivalent of the quantity.
Identity
A number that when an operation is applied to a given number yields that given number. For multiplication, the identity is one and for addition the identity is zero.
Identity Law
States that any expression is equal to itself.
IFF
If and only if.
Imaginary Axis
The y-axis of an Argand diagram.
Imaginary Number
i denotes the imaginary number formed by square rooting negative one.
Imaginary Part
The imaginary part of a complex number.
Included Side
The side between two angles in a polygon.
Inclusive Or
One or the other, or both.
Inconsistent Linear System
A system of linear equations is inconsistent if it has no solutions.
Indefinitely
An unspecified amount, having no exact limits.
Independent Events
Two events A and B are independent if the probability that they happen at the same time is the product of the probabilities that each occurs individually.
Independent Variable
One that is associated with the inputs to a function.
Inequality
A relationship between two expressions that are not equal.
Infinite
Becoming large beyond bound.
Infinitesimal
A variable that approaches zero as a limit.
Infinity
A reference to a quantity larger than any specific integer.
Inflection
A point of inflection of a plane curve is a point where the curve has a stationary tangent, at which the tangent is changing from rotating in one direction to rotating in the oppostie direction.
Initial Side
The side that the measurement of an angle starts from.
Initiator
A line-segment or figure that begins as the beginning geometric shape for a fractal.
Inner Product
The inner or dot product of two vectors is obtained by adding the products of the respective components of the vectors.
Input
The number or value that is entered, for example, into a function machine.
Integer
A whole number.
Intercept
The point where two lines drawn on a graph cross each other.
Intersecting Planes
Planes that share a line.
Intersection Law
States that if one input to an AND gate is already TRUE, then the output will depend upon the state of the other inputs only.
Intersection of Sets
The intersection of two or more sets is the set of elements that all the sets have in common.
Inverse of a Matrix
The matrix B is an inverse for the matrix A if AB = BA = I.
Inverse Proportionality
A relationship in which a quantity is related to the reciprocal of a second quantity.
Inverse Square
A relationship in which a quantity is related to the reciprocal of the square of a second quantity.
Inversely
Inverted or reversed in position or relationship.
Invert
To change a physical or logical state to its opposite state.
Invertible
A function, f(x), is invertible if there is a function, g(x), which is its inverse.
Invertible Matrix
A matrix is invertible if it has an inverse.
Irrational Number
Any number that cannot be expressed as the ratio of two integers.
Irregular Fractals
Complex fractals whose dimension is often difficult to determine and in some cases is unknown.
Isometry
A transformation that keeps the same size and shape of a figure but moves it to a new location.
Isomorphism
A mapping between objects which shows a relationship between two properties or operations.
Iteration
Repeating a set of rules or steps over and over.
j
j is used in engineering and physics to represent i the imaginary number.
Joint Probability
The probability of two or more events happening at the same time.
Joint Variation
A variation in which the values of one variable depend upon those of 2 or more variables.
Jordan Curve
A simple closed curve.
Jordan Matrix
A matrix whose diagonal elements are all equal (and nonzero) and whose elements above the principal diagonal are equal to 1, but all other elements are 0.
Julia Set
The set of all the points for a function of the form Z^2+C.
Jump Discontinuity
A discontinuity in a function where the left and right-hand limits exist but are not equal to each other.
Kalman Filter
A technique for estimating an unknown state of a linear dynamic system given observations of the system which have additive (Gaussian) noise.
Knight′s Tour
A knight's tour of a chessboard is a sequence of moves by a knight such that each square of the board is visited exactly once.
Laplace Transform
The Laplace transform is used to convert certain types of inital value problems into algebra problems.
Laplacian
The divergence of a gradient.
Latin Square
An n by n array of numbers in which only n numbers appear. No number appears more than once in any row or column.
Latitude
The angular distance of a point on the Earth from the equator.
Lattice Point
A point with integer coordinates.
Least Significant Bit (LSB)
The bit within a digital word that represents the smallest possible coded value.
Least Squares
Any statistical procedure that involves minimizing the sum of squared differences.
Least Upper Bound
The least upper bound of a set of numbers is the smallest number that is larger than every member of the set.
Lemata
The plural of Lemma.
Lemma
A proposition that is useful mainly for the proof of some other theorem.
Lempel-Ziv Welch Compression
Algorithm used by the Unix compress command to reduce the size of files, eg. for archival or transmission.
Leonardo of Pisa
Fibonacci was also known as Leonardo of Pisa.
Leptokurtic
A distribution that is more peaked than a normal distribution.
Less Than
An inequality that says the variable on the left is less than the variable to the right of the inequality.
Less than or Equal to
An inequality that says the variable on the left is less than or equal to the variable to the right of the inequality.
Limit
The number you approach as you plug values into a function, and the values get closer and closer to a given number.
Line
Line is one of the basic undefined terms in Euclidian geometry, but one intuitive definition is as follows: A straight set of points that continue on to infinity in both directions. Although a line is of infinite length, it has thickness and width of zero.
Line Graph
A diagram showing a system of connections or interrelations between two or more things by using lines.
Line of Best Fit
A straight line used as a best approximation of a summary of all the points in a scatter-plot.
Line of Reflection
The line that is reflected over in a reflection.
Line Plot
A graphical display of a set of data where each separate piece of data is shown as a dot or mark above a number line.
Line Segment
A piece of a line which includes two definite endpoints and all points in between them.
Line Symmetry
If a figure is divided by a line and both divisions are mirrors of each other, the figure has line symmetry.
Linear
Having an output that varies in direct proportion to the input.
Linear Regression
An attempt to model the relationship between two variables by fitting a linear equation to observed data.
ln
Abbreviation of Natural Logarithm.
Locus
The set of all points meeting some specified condition.
log
Abbreviation of Logarithm.
Logic
The study of the formal laws of reasoning.
Logistic Equation
A classical starting point for the dynamics of quasiperiodic and chaotic systems.
Lorentz Transformation
A set of equations which are used, in relativity problems, to transform measurements from one frame of reference to another.
Lowest Terms
A fraction is said to be in lowest terms if its numerator and denominator have no common factor.
LSB
Abbreviation of Least Significant Bit, the bit within a digital word that represents the smallest possible coded value.
Lucas Number
A member of the sequence 2, 1, 3, 4, 7,... where each number is the sum of the previous two numbers.
Lune
The portion of a sphere between two great semicircles having common endpoints, including the semicircles.
Magic Square
A square array of n numbers such that sum of the n numbers in any row, column, or main diagonal is a constant.
Magic Tour
If a chess piece visits each square of a chessboard in succession, this is called a tour of the chessboard.
Main Diagonal
In the matrix [aij], the elements a11, a22, ..., ann.
Major Axis
The major axis of an ellipse is it′s longest chord.
Mandelbrot Set
The most famous fractal, named after Benoit Mandelbrot. It is created by iterating an equation many times.
Mathematical Model
A mathematical representation of a process or physical object.
Mathematical Symbols
Common symbols used in mathematics.
Matrix
A rectangular array of elements.
Maxima
The maxima are points where the value of a function is greater than other surrounding points.
Maximum
In a sample of data, the largest observation.
Median
A statistic which measures the centre of a set of data by finding that value which divides the data in half.
Mersenne Number
A number of the form 2p-1 where p is a prime.
Mersenne Prime
A Mersenne number that is prime.
Mesokurtic
A distribution that is normal.
Minima
The minima are points where the value of a function is less than other surrounding points.
Minimum
In a sample of data, the smallest observation.
Minor Axis
The minor axis of an ellipse is its smallest chord.
Minuend
A number from which another number is to be subtracted.
Minus
The symbol: -
Mixed Numbers
Numbers that have both whole numbers and fractions, such as 3 3/4.
Modular Arithmetic
This is can be used as method for finding remainders where all the possible numbers (the numbers less than the divisor) are put in a circle, and then by counting around the circle the number of times of the number being divided, the remainder will be the final number landed on.
Modular Number System
A number system represented best by numbers on a circle because the numbers repeat.
Modulo
The integers a and b are said to be congruent modulo m if a-b is divisible by m.
Modulus
The absolute value of a quantity, not considering it's sign or direction.
Monic Polynomial
A polynomial in which the coefficient of the term of highest degree is 1.
Monomial
An algebraic expression consisting of just one term.
Monotone
A sequence is monotone if its terms are increasing or decreasing.
Monotonic
Designating sequences, the successive members of which either consistently increase or decrease but do not oscillate in relative value.
Montone
A sequence is monotone if its terms are all increasing or all decreasing.
Moving Average
The average of the most recent n data values.
Natural Number
Any one of the numbers 1, 2, 3, 4, 5, ..
Negation
The process of inverting the value of a function or variable.
Negative
A quantity or value that is less than zero.
Negative Numbers
Numbers that are less than zero are negative numbers.
Network
A group of nodes and arcs.
Newton, Isaac
Newton was a mathematician and natural philosopher (physicist).
Nomograph
A graphical device used for computation which uses a straight edge and several scales of numbers.
Nonagonal Number
A number of the form n(7n-5)/2.
Nonary
Associated with 9.
Nonillion
A number equal to 1030.
Nonsingular Matrix
A square matrix A is nonsingular if the only solution to the equation Ax = 0 is x = 0.
Nonstationary
A characteristic of a time series for which the distribution changes over time.
Normal
A line perpendicular to a surface or curve.
not equal to
A definite statement that the quantity on the left hand side is not equal to the quantity on the right hand side.
Null Hypothesis
Proposes a general or default position, such as that there is no relationship between two measured phenomena, or that a potential treatment has no effect.
Null Set
The null set is a set that contains no objects. Also known as the empty set.
Number
A mathematical entity that may indicate quantity or amount of units.
Number Line
A line on which each point represents a real number.
Number Representation
The representation of numbers by agreed sets of symbols according to agreed rules.
Number System
Any system for the representation of numbers.
Numeral
A numeral is just an object or symbol that stands for a number. For example, 5 is the Arabic numeral for five, and V the Roman numeral for five.
Numerator
The quantity or value on the top of a fraction.
Numerical Analysis
The study of methods for approximation of solutions of various classes of mathematical problems including error analysis.
Oblate Spheroid
An ellipsoid produced by rotating an ellipse through 360° about its minor axis.
Oblique Coordinates
A coordinate system in which the axes are not perpendicular.
Observation
Observations refer to repeated values of a data variable. The rows of a column represent the observations.
Octal
A number system using the base-8, i.e., each digit can be any of 8 values, represented by the digits 0-7.
Octant
Any one of the 8 portions of space determined by the 3 coordinate planes.
Octillion
A number equal to 1027.
Odd Function
A function f(x) is called an odd function if f(x)=-f(-x) for all x.
Odd Number
An integer that is not divisible by 2.
of the order of
Used when estimating a quantity and means that it is roughly equal to.
Offset Binary Coding
For bipolar signals, offset binary is a digital coding scheme in which the most negative value is represented by all zeros (00000000) and the most positive value is represented by all ones (11111111).
One to One
A function f is said to be one to one if f(x)=f(y) implies that x=y.
Open Interval
An interval that does not include its two endpoints.
Opposite Faces
Faces that lie in parallel planes.
Ordered Pair
A pair of numbers in which one number is distinguished as the first number and the other as the second number of the pair.
Ordinal Number
A number indicating the order of a thing in a series.
Ordinate
The y-coordinate of a point in the plane.
Origin
In Cartesian coordinates, it is the point (0, 0) and located at the intersection of the x- and y-axes.
Orthocentre
The point of intersection of the altitudes of a triangle.
Orthogonal
Mutually perpendicular.
Orthogonal Matrix
A matrix A is orthogonal if A is invertible and its inverse equals its transpose; i.e., A-1 = AT.
Outcome
Any one of the possible results of an experiment.
Outcome Space
Another name for Sample Space.
Outlier
A data value which is unusual with respect to the group of data in which it is found.
Output
The number or value that comes out from a process.
Palindrome
A positive integer whose digits read the same forward and backwards.
Palindromic
A positive integer is said to be palindromic with respect to a base b if its representation in base b reads the same from left to right as from right to left.
Pandiagonal Magic Square
A magic square in which all the broken diagonals as well as the main diagonals add up to the magic constant.
Pandigital
A decimal integer is called pandigital if it contains each of the digits from 0 to 9.
Paraboloid
A paraboloid of revolution is a surface of revolution produced by rotating a parabola about its axis.
Paradox
A statement that appears to contradict itself, for example, suggesting a solution which is actually impossible.
Parallel
Two or more lines are said to be parallel if they are in the same plane, but never intersect. Two or more planes are parallel if the planes never intersect.
Parallel Planes
Planes that have no points in common.
Parallelepiped
A prism whose bases are parallelograms.
Parallelogram
A quadrilateral in which opposite sides are parallel.
Parenthesis
The symbols ( and ) used for grouping expressions.
Pascal′s Triangle
Each number is the sum of the two numbers above. The sum of each row is equal to a power of 2.
Pattern
Recognizable regularities in situations such as in nature, shapes, events, sets of numbers.
Peak
Extreme value of a varying quantity, measured from the zero or mean value.
Pearson Product Moment Correlation Coefficient
A dimensionless index that reflects the extent of a linear relationship between two data sets.
Pell Number
The nth term in the sequence 0, 1, 2, 5, 12,... defined by the recurrence P0=0, P1=1, and Pn=2Pn-1+Pn-2.
Penrose Impossible Staircase
A four sided staircase that always goes up if you travel around it in one direction and always down if you travel in the opposite direction.
Pentagonal Number
A number of the form n(3n-1)/2.
Pentagram
A star shaped figure constructed by extending all of the sides of a regular pentagon until they meet at the points of the star.
Percent
A ratio that compares a number to one hundred.
Percentile
A value on a scale that indicates the percent of a distribution that is equal to it or below it.
Perfect Number
A positive integer that is equal to the sum of its proper divisors.
Perfect Power
An integer is a perfect power if it is of the form mn where m and n are integers and n>1.
Perfect Square
An integer is a perfect square if it is of the form m2 where m is an integer.
Perimeter
The distance around the outside of a shape.
Permutations and Combinations
A permutation is a particular sequence of a given set of objects. A combination is the set itself without reference to order.
Perpendicular
At right angles to. A line at right angles to another line or to a plane.
Perspective
A feeling of depth.
Perspective Drawing
A drawing in which, in order to show perspective, oblique parallel lines will meet.
pi
A letter of the Greek alphabet. The lowercase is used to denote the number of times the diameter of a circle can be divided into the circumference.
Pie Chart
A strong representation of data with the size of the slice representing the fraction of the total.
Piecewise Function
A function is piecewise-defined, if its rule is given by more than one other formula for different sets of input.
Place Value
Within a number, each digit is given a place value depending on it′s location within the number.
Plane
A two-dimensional group of points that goes on infinitely in all directions; made up of infinite lines.
Plane Section
The intersection of a figure with a plane.
Plato
A Greek philosopher, pupil of Socrates and Aristotle′s teacher.
Platykurtic
A distribution that is less peaked than a normal distribution.
Plus
The symbol: +
Point
A zero-dimensional figure.
Poisson Equation
A fundamental equation of mathematical physics, describing the spatial variation of a potential function for given source terms.
Polar Axis
In the polar coordinate system, a ray from the pole in a fixed direction, analogous to the x-axis in the Cartesian system.
Polar Coordinates
The position of a point is defined as the distance from the origin and an angle relative to the x axis.
Polar Form of Complex Numbers
Complex numbers written in polar form.
Polyhedral
In the shape of a solid formed by plane faces, as in a prism.
Polynomial
A function that is a sum of power functions, with positive integer exponents, multiplied by constants.
Population
The total number of unique values.
Positional Notation
A numbering system in which a number is represented by means of a stated set of symbols or digits, such that the value contributed by each symbol or digit depends upon its position as well as upon its value.
Positional Weighting
The value given a digit based on the digit′s position within a given number.
Positive
A quantity or value that is greater than zero.
Positive Logic
The form of logic in which the more positive logic level represents 1 and the more negative level represents 0.
Positive Number
A number larger than 0.
Postulate
A statement assumed to be true without proof.
Practical Number
A positive integer m such that every natural number n not exceeding m is a sum of distinct divisors of m.
Prime Numbers
A prime number has only two different factors. They are 1 and the number itself. 13 is a prime number because the only factors of 13 are 1 and 13. Note that 1 is not a prime number.
Primitive Root of Unity
The complex number z is a primitive nth root of unity if zn=1 but zk is not equal to 1 for any positive integer k less than n.
Principal Component Analysis
Constructing new features which are the principal components of a data set.
Principal Curve
A nonlinear principal component axis.
Probability
A number between 0 and 1 which represents how likely an event is to occur.
Prolate Spheroid
An ellipsoid of revolution, the longer axis of which is the axis of revolution.
Pronic Number
A number of the form n(n+1).
Proper Divisor
The integer d is a proper divisor of the integer n if 0
Proportion
A statement of equality between two ratios.
Proportionality
A relationship in which a quantity is related to the second quantity.
Protractor
A tool used to measure angles.
PSD
A method of scaling the amplitude axis of spectra of random rather than deterministic signals.
psi
A letter of the Greek alphabet.
Pythagoras
Greek philosopher and mathematician; held that numbers were basic to matter.
Pythagoras Theorem
The Square on the Hypotenuse is equal to the sum of the squares of the other two sides.
Pythagorean Triple
An ordered set of three positive integers (a,b,c) such that a2+b2=c2.
QED
Abbreviation for quod erat demonstrandum, used to denote the end of a proof.
Quadrant
In Cartesian Coordinate geometry, the coordinate plane is divided into four quadrants.
Quadric Curve
The graph of a second degree equation in two variables.
Quadric Surface
The graph of a second degree equation in three variables.
Quadrilateral
A four sided polygon.
Quadrillion
A number equal to 1015.
Quart
A unit of volume.
Quarter
One of four equal parts. An outdated British unit of weight 1 quarter = 28 pounds (lb).
Quartic
A polynomial equation of degree 4.
Quartiles
Statistics which divide the observations in a numeric sample into 4 intervals, each containing 25% of the data.
Quintic
A polynomial equation of degree 5.
Quintile
Statistics which divide the observations in a numeric sample into 5 intervals.
Quintillion
A number equal to 1018.
Quod Erat Demonstrandum
Normally abbreviated as QED and used to denote the end of a proof.
Quotient
The result when one number or quantity is divided by another.
rad
An abbreviation of radian the SI unit of plane angle.
Radial
A direction perpendicular to the centreline of a shaft.
Radii
Plural of radius.
Radius
In a circle, the radius is the distance from the centre of the circle to a point on the circle.
Radix
The number of distinct symbols used in a number system.
Random Noise
A noise signal, commonly used in measurements, which has constantly shifting amplitude, phase, and a uniform spectral distribution of energy.
Random Number Generators
A device used to produce a selection of numbers in a fair manner, in no particular order and with no favour being given to any numbers.
Random Process
A random process is a collection of time-history records that can be described by appropriate statistical parameters, such as averaged properties of these records at a number of fixed times.
Random Sampling
A sampling method in which all elements in the population have an equal chance of being selected.
Rate of Change
The speed at which a function is changing.
Ratio
The quotient of two numbers.
Rational B-Spline
equation that permits the modeling of free-form curves between two endpoints as a function of a set of intermediate points whose values influence the shape of the curve.
Rational Number
Any number that can be expressed as the ratio of two integers.
Rayleigh′s Method
A method used for calculating approximate natural frequencies for a vibrating system assuming a deflected shape and balancing kinetic and strain energies.
Real Axis
The x-axis of an Argand diagram.
Real Number
Any of the conventional numbers, including fractions and irrationals.
Real Part
The real number x is called the real part of the complex number x+iy where x and y are real and i=sqrt(-1).
Real Variable
A variable whose value ranges over the real numbers.
Recency Effect
An increase in correct recall rate for the most recently presented items of a list compared with those presented earlier in the list.
Reciprocal
A number that is made into a fraction.The reciprocal of 2 is 1/2.
Rectangular Coordinates
Coordinates where the position of a point is described by the distance it is from 2 lines in 2 dimensional space or from 3 planes in 3 dimensional space.
Recursion
Given some starting information and a rule for how to use it to get new information, the rule is then repeated using the new information.
Reflect
In a tessellation, reflect means to repeat an image by flipping it across a line so it appears as it would in a mirror.
Relative Frequency
A count of the number of occurrences of a data value in a sample, or the number of values falling within a fixed range, expressed as a proportion of the total number of observations.
Relatively Prime
If the greatest common divisor of a and b is 1 then a and b are known as relatively prime.
Repdigit
An integer all of whose digits are the same.
Repeating Decimal
A decimal whose digits eventually repeat.
Repunit
An integer consisting only of 1′s.
Residual
The observed value minus the predicted value.
Resolver
A rotary, electromechanical device used to perform trigonometric computations by varying the magnetic couplings between its primary and secondary windings.
Revolution
A rotation through a full circle, or 360 degrees.
Rhombus
A parallelogram with four equal sides.
Roman Numerals
The roman number system with decimal equivalents.
Root
A root of a polynomial function, f, is just a solution to the equation f(x) = 0, that is an input that yields an output of 0.
Root of Unity
A solution of the equation xn=1, where n is a positive integer.
Rosenbrock Function
A non-convex function used as a performance test problem for optimization algorithms introduced by Rosenbrock in 1960.
Rotate
To rotate an object in a tessellation means to repeat the object by spinning it on a point a certain angle.
Rotation
Motion of an object where the path of every point is a circle or circular arc.
Round Off Error
This is error introduced into a calculation by rounding off the results of intermediate steps to values which are close, but not exactly correct.
Rounding
A numerical value means replacing it by another value that is approximately equal but has a shorter, simpler, or more explicit representation.
Round-Off Error
The error accumulated during a calculation due to rounding intermediate results.
Row Equivalent Matrices
Two matrices are row equivalent if one can be obtained from the other by a sequence of elementary row operations.
Ruled Surface
A surface formed by moving a straight line.
Rusty Compass
A pair of compasses that are fixed open in a given position.
Sample
A set of observations, usually considered to have been taken from a much larger population.
Sample Space
The set of all possible outcomes of a given experiment.
Scalar Product
The scalar or dot product of two vectors is obtained by adding the products of the respective components of the vectors.
Scaling
The process of drawing a figure either enlarged or reduced in size from its original size.
Scatter Plot
A graphical representation of the distribution of two random variables as a set of points whose coordinates represent their observed paired values.
Scientific Notation
Numbers entered as a number from one to ten multiplied by a power of ten.
Secant Line
A line that intersects a curve or circle in two places.
Second Derivative
The derivative that comes after the first derivative and before the third derivative. Obtained by taking the derivative of a function twice in a row.
Sector
A non-overlapping piece of an object.
Self Similarity
Two or more objects having the same characteristics.
Semi-Magic Square
A square array of n numbers such that sum of the n numbers in any row or column is a constant (known as the magic sum).
Separable Equations
A differential equation is separable if it can be written: y′=A(x)B(y)
Septet
A unit of quantity equal to 7.
Septillion
A number equal to 1024.
Sequence
An ordered set whose elements are usually determined based on some function of the counting numbers.
Series
The sum of a finite or infinite sequence.
Set
A collection of objects called elements.
Sexadecimal
The same as Hexadecimal.
Sexagesimal
In the sexagesimal system calculations are done in the base 60 as used by the Ancient Babylonians.
Sextet
A unit of quantity equal to 6.
Sextillion
A number equal to 1021.
Shapiro-Wilks Test
A test to determine whether or not a sample comes from a normal distribution.
Sign
The sympol that states whether a number is positive (+) or negative (-). If a sign is not placed immediately before a number, it is taken as positive.
Significant Digits
The number of digits to consider when using measuring numbers.
Signs and Symbols
A list of signs and symbols.
Similarity
The relationship between two objects that have exactly the same shape but not necessarily the same size.
Singular Matrix
A square matrix A is singular if the equation Ax = 0 has a nonzero solution for x.
Sinusoidal
Having the form of a sine wave.
Skeleton Division
A long division in which most or all of the digits have been replaced by asterisks to form a cryptarithm.
Skew
An expression of the so-called "third moment".
Skewness
Skewness defines the degree of asymmetry of the distribution around its central value.
Slide Rule
A calculating device consisting of two sliding logarithmic scales.
Slope
The measure of the tilt of a line, the rise over run or how much the line moves up for every movement to the right.
Slope of a Linear Function
The slope of the line y = mx + b is the rate at which y is changing per unit of change in x.
Smoothing
Smoothing techniques are used to reduce irregularities in time series data.
Socrates
Greek philosopher; emphasized the study of human nature in relationship to society.
Solid of Revolution
A solid formed by rotation a plane figure about an axis in three-space.
Space
The set of all possible points; made up of infinite planes.
Special Constants
A list of Mathematical constansts and their formulations.
Spherical Coordinates
A point is located in space by the distance from the origin and two angles.
Square
A number raised to the power 2 ie 2 x 2 = 22 = 4. Also, a 2 dimensional figure with the height and width having the same lengths,and at right angles to each other.
Square Free
An integer is said to be square free if it is not divisible by a perfect square, n2, for n>1.
Square Root
The square root of a number is a number that when multiplied by itself equals the number that the square root is being taken of.
Square Surface
A surface at a right angle with another surface.
Standard Integrals
A listing of the standard indefinite and definite integrals.
Standardized Kurtosis
A standardized form of the kurtosis statistic which renders the statistic free of scale.
Standardized Skewness
A standardized form of the skewness statistic which renders the statistic free of scale.
Statistics
Lists all Statistics topics in the Encyclopaedia
Statistics Books
Lists all Statistics Books in the Encyclopaedia
Statistics Calculations
Lists all Statistics Calculations in the Encyclopaedia
Statistics Conversions
Lists all Statistics Conversions in the Encyclopaedia
Statistics Weblinks
Lists all Statistics Weblinks in the Encyclopaedia
Straight Line
A straight set of points that continue on to infinity in both directions.
Straightedge
As it sounds, an unmarked tool used to draw straight lines.
Subset
A subset of a given set is a collection of things that belong to the original set.
Subtrahend
A number that is to be subtracted from another number.
Sum
The result of the addition of numbers.
Superscript
Numbers or letters written above and to the right of other numbers or letters or symbols indicating how many times the latter is to be used as a factor.
Surd
Used in mathematics to describe an irrational quantity.
Surface Area
The total area of the surface of a solid.
Symbolic Logic
A mathematical form in which propositions and their relationships may be represented symbolically.
Symmetric Matrix
A matrix A is symmetric if it equals its transpose.
Symmetry
A figure has symmetry if it has parts that correspond with each other in terms of size, form, and arrangement.
Target Population
The entire group a researcher is interested in, the group about which the researcher wishes to draw conclusions.
Terminal Side
The side that the measurement of an angle ends at.
Tesselation
A covering of a plane with congruent copies of the same region with no holes or overlaps.
Theoretical Probability
The chances of events happening as determined by calculating results that would occur under ideal circumstances.
Thousand
A number equal to 103.
Tilt
The measure of an angle as compared to a horizontal line.
Timeline
A brief overview of the major milestones in science and engineering.
Toeplitz Matrix
A matrix in which all the elements are the same along any diagonal that slopes from northwest to southeast.
Tomography
Mathematical techniques for reconstructing three dimensional volumes from the integrated projections along rays.
Torus
A geometric solid in the shape of a doughnut.
Total
The overall sum of numbers or a quantity.
Trace
The trace of a matrix is the sum of the terms along the principal diagonal.
Transcendental
Not algebraic.
Transform
A transform is a mathematical operation that converts a function from one domain to another domain with no loss of information.
Transformation
A change in the size, shape, location or orientation of a figure.
Translate
In a tessellation, to translate an object means repeating it by sliding it over a certain distance in a certain direction.
Transversal
A line that intersects 2 others.
Transversible
A network in which all arcs can be traced without going over one more than once.
Trapezoid
A quadrilateral that has at least one pair of parallel sides.
Tree Diagram
A schematic way of showing the number of ways a compound event may occur.
Triad
A unit of quantity equal to three.
Triangular Number
A number of the form n(n+1)/2.
Triangulation
In general, the unique location of the source from some combination of at least three ranges and/or bearings in three dimensional space.
Trigonometry
Lists all Trigonometry topics in the Encyclopaedia
Trilateration
Method of surveying wherein the lengths of the triangle sides are measured.
Trillion
A number equal to 1012.
Triple
A group of three items.
Truncate
To eliminate without round-off some low-order bits, often after performing an arithmetic computation.
Truncated Paraboloid
A paraboloid reflector that has been cut away at the top and bottom.
Truncation Error
Error resulting from the use of only a finite number of terms of an infinite series or from the approximation of operations.
t test
A hypothesis test based on Student′s t distribution.
Twin Primes
Two prime numbers that differ by 2. eg 11 and 13.
Unilateral Surface
A surface with only one side, such as a Moebius strip.
Unimodal
A finite sequence is unimodal if it first increases and then decreases.
Unimodular Matrix
A square matrix is unimodular if its determinant is 1.
Union of Sets
The union of two or more sets is the set of all the objects contained by at least one of the sets.
Unitary Divisor
A divisor d of c is called unitary if gcd(d,c/d) = 1.
Unity
One.
Universal Statement
A conditional that uses the words "all" or "everything".
Upper Quartile
The 75th percentile, calculated by ordering the data from smallest to largest and finding the value which lies 75% of the way up through the data.
Vanishing Line
The horizon; in a drawing it is at the height of viewer′s eye.
Vanishing Point
The point in space where two parallel lines seem to meet.
Variable
A letter that is used to represent a numerical quantity whose value may or may not yet be known.
Variate
Random variable.
Venn Diagram
A diagram where sets are represented as simple geometric figures, with overlapping and similarity of sets represented by intersections and unions of the figures.
Versus
As a function of, as distance versus time.
Vertical
The direction of gravity at the point of observation.
Vertical Axis
On a graph, the straight line axis that is plotted from bottom to top, the y axis.
Vertical Line
A line that goes straight up and down, and whose slope is defined as infinite or undefined.
Vertical Plane
An imaginary plane that is perpendicular to the horizontal plane.
Vigesimal
Related to intervals of 20.
Vinculum
The horizontal bar in a fraction separating the numerator from the denominator.
Warning Limits
Limits placed on a control chart for variables or attributes at 1 and 2 sigma to help determine how far points lie from the centerline.
Waterfall Plot
A series of spectral maps taken at regular intervals of time or at regularly spaced shaft speeds, similar to the flow of a waterfall.
Weak Inequality
An inequality that permits the equality case. For example, a is less than or equal to b.
Winding Number
The number of times a closed curve in the plane passes around a given point in the counter clockwise direction.
Witch of Agnesi
A curve whose equation is x2y=4a2(2a-y).
Working Stress
The allowable stress considered to be safe in the design of part. It is the ultimate stress of the material divided by a safety factor.
X
Roman numeral for 10.
x axis
The horizontal axis in the plane.
X-Intercept
The point at which a line crosses the x-axis.
y axis
The vertical axis in the plane.
Y-Intercept
The point at which a line crosses the y-axis.
Z Axis
Axis perpendicular to both X and Y axes.
Zero Element
The element 0 is a zero element of a group if a+0=a and 0+a=a for all elements a.
Z-Intercept
The point at which a line crosses the z-axis.

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