Header File 

math.h  

Category 

Math Routines 

Prototype 

double cosh(double x); 

long double coshl(long double x); 

Description 

Calculates the hyperbolic cosine of a value. 

cosh computes the hyperbolic cosine: 

coshl is the long double version; it takes a long double argument and returns a long double result. 

Return Value 

cosh returns the hyperbolic cosine of the argument. 

When the correct value would create an overflow, these functions return the value HUGE_VAL (cosh) or _LHUGE_VAL (coshl) with the appropriate sign, and the global variable errno is set to ERANGE. Error handling for these functions can be modified through the functions _matherr and _matherrl. 

Example  

#include <stdio.h>
#include <math.h>
int main(void)
{
   double result;
   double x = 0.5;
   result = cosh(x);
   printf("The hyperbolic cosine of %lf is %lf\n", x, result);
   return 0;
}

Portability