7.12.4.3 The atan functions

Synopsis

1

#include <math.h>
double atan(double x);
float atanf(float x);
long double atanl(long double x);

Description

2

The atan functions compute the principal value of the arc tangent of x.

Returns

3

The atan functions return arctan x in the interval [-pi /2, +pi /2] radians.