{{keywords>wiki library source code example reference}}
===== tanh =====
<code c>
    double tanh(double);
</code>
Returns hyperbolic tangent of a radian angle x. 

===== C Sourcecode Example =====
compile with tanh.c -o tanh **-lm**
<code c>
#include <stdio.h> /* including standard library */
//#include <windows.h> /* uncomment this for Windows */

#include <math.h> /* including math library */

int main( void )
{
    double x;
    x = log(42);
    printf ("hyperbolic tangent of 42 is %lf\n", tanh (x) );
    return 0;
}
</code>

==== output ====
   output:
   user@host:~$ ./tanh 
   hyperbolic tangent of 42 is 0.998867