# Trigonometric Functions

Sine: Sin(x) = x - x^3 / 3! + x^5 / 5! ...
See: Sine -- From MathWorld
and Wolfram Function Evaluation

Cosine: Cos(x) = Sin(x + Pi/2).
See: Cosine -- From MathWorld
and Wolfram Function Evaluation

Tangent: Tan(x) = Sin(x) / SqRt(1 - Sq(Sin(x)), and change sign
of Tan(x) if in 2nd or 3rd quadrant,
error if x is equivalent to plus or minus 90 degrees.
See: Tangent -- From MathWorld
and Wolfram Function Evaluation

Cotangent: Cot(x) = 1/Tan(x), error if Tan(x) = 0
i.e. error if x is equivalent to zero or 180 degrees.
Cot(x) = 0 if x is equivalent to plus or minus 90 degrees.
See: Cotangent -- From MathWorld
and Wolfram Function Evaluation

Secant: Sec(x) = 1/Cos(x), error if Cos(x) = 0
i.e. error if x is equivalent to plus or minus 90 degrees.
See: Secant -- From MathWorld
and Wolfram Function Evaluation

Cosecant: Csc(x) = 1/Sin(x), error if Sin(x) = 0
i.e. error if x is equivalent to zero or 180 degrees.
See: Cosecant -- From MathWorld
and Wolfram Function Evaluation

See: Transcendental Function Evaluation