Arc tangent

[Classification]

Mathematical library

[Syntax]

#include <mathf.h>

float atanf(float x);

[Return value]

Returns the arc tangent (arctangent) of x. The returned value is in radian and in a range of -p / 2 to p / 2.

If the solution is a denormal number, atanf sets macro ERANGE to global variable errno.

[Description]

This function calculates the arc tangent (arctangent) of x. Specify x as, -1 <= x <= 1.

[Example]

#include    <mathf.h>

float func(float x) {

        float   ret;

        ret = atanf(x); /*Returns value of arctangent of x to ret.*/

          :

        return(ret);

}