Hyperbolic cosine
[Classification]
Mathematical library
[Syntax]
#include <math.h>
long double __far coshl(long double x); (C99)
[Return value]
Returns the hyperbolic cosine of x.
coshl returns ∞ 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