The function **double tanh(double x);** returns the hyperbolic tangent of x radians.

## Function prototype of tanh

*double tanh(double x);***x**: A floating point value representing an angle in radians.

## Return value of tanh

It returns the hyperbolic tangent of x.

## C program using tanh function

The following program shows the use of tanh function to calculate hyperbolic tangent of an angle in radian.

#include <stdio.h> #include <math.h> int main(){ double value, radian; printf("Enter a number\n"); scanf("%lf", &radian); value = tanh(radian); printf("The hyperbolic tangent of %lf is %lf\n", radian, value); return 0; }

Output

Enter a number 0.5 The hyperbolic tangent of 0.500000 is 0.462117