atan function

Converts x to a dobule and returns the arc tangent of the vlaue. Returns a value in the range -PI/2..PI/2, or NaN if x is NaN.

double atan(
num x
)

Converts x to a dobule and returns the arc tangent of the vlaue. Returns a value in the range -PI/2..PI/2, or NaN if x is NaN.