cosh

    double cosh(double);

calculates the hyperbolic cosine of a number

#include <iostream> /* including standard library */
#include <cmath> /* including math library */
 
using namespace std;
int main ( void ) 
{
    double x,res;
    x = log(1.3);
    res = cosh(x);
 
    //cout.setf(ios::fixed, ios::floatfield);
    cout.precision(8);   
 
    cout << "The log is " << x << endl;
    cout << "the hyperbolic cosine of " << x << " is " << res << endl;
    return 0;
}

  The log is 0.26236426
  the hyperbolic cosine of 0.26236426 is 1.0346154