Hyperbolic cosine

[Classification]

Mathematical library

[Syntax]

#include <mathf.h>

float coshf(float x);

[Return value]

Returns the hyperbolic cosine of x.

coshf returns HUGE_VAL and sets macro ERANGE to global variable errno if an overflow occurs.

[Description]

This function calculates the hyperbolic cosine of x. Specify the angle in radian. The definition expression is as follows.

(e x + e -x) / 2

[Example]

#include    <mathf.h>

float func(float x) {

        float   ret;

        ret = coshf(x);     /*Returns value of hyperbolic cosine of x to ret.*/

          :

        return(ret);

}