- hyperbolic tangent function
c99 [ flag... ] file... -lm [ library... ] #include <math.h> double tanh(double x);
float tanhf(float x);
long double tanhl(long double x);
These functions compute the hyperbolic tangent of their argument x.
Upon successful completion, these functions return the hyperbolic tangent of x.
If x is NaN, a NaN is returned.
If x is ±0, x is returned.
If x is ±Inf, ±1 is returned.
No errors are defined.
See attributes(5) for descriptions of the following attributes: