NAME
sinh, cosh, tanh, asinh, acosh, atanh - hyperbolic functions and
their inverses

SYNOPSIS
#include <math.h>

double sinh(x)
double x;

double cosh(x)
double x;

double tanh(x)
double x;

double asinh(x)
double x;

double acosh(x)
double x;

double atanh(x)
double x;

DESCRIPTION
These functions compute the designated direct and inverse
hyperbolic functions for real arguments.

DIAGNOSTICS
Sinh() and cosh() return +-INF on an overflow.

Acosh(x) returns NaN if x < 1.

Atanh(x) returns NaN if |x| > 1, and +-INF if |x| = 1.