Cosine

 Note: In this series A is in radians.
 Note: Valid for 0 ≤ A ≤ π/2
 Note: Valid for 0 ≤ A ≤ π/2
 The following expression is also known as the half angle formula:
 Inverse trigonometric functions
 Inverse trigonometric functions are often written as arccos(A) or cos^{1}(A)
 Note: Valid for 0 ≤ A ≤ π/2
See also: Cosecant, Cotangent, Secant, Series Expansions, Sine, Tangent, Trigonometric Functions.
Subjects: Trigonometry