#include <math.h>
double sinh(double x);
sinh calculates the hyperbolic sine of x.
If |x| >~ 709.782, errno is set to EDOM and sinh returns HUGE_VAL.
If x is +∞, -∞, or NaN, sinh returns |x|.
If |x| >~ 709.782, sinh returns +∞ or
-∞ depending upon the sign of x.
sinh conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).