tanh, tanhf, tanhl - hyperbolic tangent function
#include <math.h>
double tanh(double x);
float tanhf(float x);
long double tanhl(long double x);Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
These functions return the hyperbolic tangent of x, which is
defined mathematically as:
tanh(x) = sinh(x) / cosh(x)On success, these functions return the hyperbolic tangent of
x.
If x is a NaN, a NaN is returned.
If x is +0 (-0), +0 (-0) is returned.
If x is positive infinity (negative infinity), +1 (-1) is
returned.