cosh() is a Mathematical Function that returns the hyperbolic cosine for the given argument. If the value returned by this function is large, then the "HUGE_VAL" is returned, by setting the "errno" to the "ERNAGE" value.

    float cosh( float arg );
    double cosh( double arg );
    long double cosh( long double arg ); 

   #include <iostream.h>
   #include <cmath.h>
   int main ()
    {
      cout << "Hyperbolic cosine of 3 is :: " << cosh(3) ;
      return 0;
    }

   Hyperbolic cosine of 3 is :: 10.0677

In the above example cosh() is used to find the hyperbolic cosine for "3".