##### Synopsis

    #include <math.h>
    float coshf(float x);

##### Description

coshf calculates the hyperbolic sine of x.

##### Fast math library behavior

If |x| >~ 88.7228, errno is set to EDOM and coshf returns HUGE_VALF.

##### IEC 60559 math library behavior

If x is +∞, -∞, or NaN, coshf returns |x|.
If |x| >~ 88.7228, coshf returns +∞ or -∞ depending upon the sign of x.

##### Portability

coshf conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).