Calculates the hyperbolic tangent of a number

#include <math.h>
double tanh ( double x);
float tanhf ( float x);         (C99)
long double tanhl ( long double x);         (C99)

The tanh( ) function returns the hyperbolic tangent of its argument x, which is defined as sinh(x)/cosh(x).

Example

double x = -0.5, y1, y2;

y1 = tanh(x);
y2 = exp(2*x);
y2 = (y2 -1) / (y2 + 1);

printf("The tanh( ) function returns     %.15f.\n", y1 );
printf("Using the function exp( ) yields %.15f.\n", y2 );

This code produces the following output:

The tanh( ) function returns     -0.462117157260010.
Using the function exp( ) yields -0.462117157260010.

See Also

sinh( ), cosh( ), atanh( ); the hyperbolic tangent and inverse tangent functions for complex numbers, ctanh( ) and catanh( )