Parameters

d

A number representing a cosine, where d must be greater than or equal to -1, but less than or equal to 1.

Returns

An angle, θ, measured in radians, such that 0 ≤ θ ≤ π

-or-

double.NaN if d < -1 or d > 1 or d equals double.NaN.

Remarks

Multiply the return value by 180/Math.PI to convert from radians to degrees.

Requirements