ultrix man page for tanh

sinh(3m)																  sinh(3m)

Name
       sinh, cosh, tanh - hyperbolic functions

Syntax
       #include <math.h>

       double sinh(x)
       double x;

       float fsinh(x)
       float x;

       double cosh(x)
       double x;

       float fcosh(x)
       float x;

       double tanh(x)
       double x;

       float ftanh(x)
       float x;

Description
       These functions compute the designated hyperbolic functions for double and float data types.

   Error
       Below 2.4 ulps (unit in the last place).

Diagnostics
       The and functions return +oo (and sinh may return -oo for negative x) if the correct value would overflow.

See Also
       math(3m)

								       RISC								  sinh(3m)