C语言库cosh()函数

#include <stdio.h>
#include <math.h>

int main () {
   double x;
   x = 0.5;
   printf("The hyperbolic cosine of %lf is %lf/n", x, cosh(x));

   x = 1.0;
   printf("The hyperbolic cosine of %lf is %lf/n", x, cosh(x));

   x = 1.5;
   printf("The hyperbolic cosine of %lf is %lf/n", x, cosh(x));

   return(0);
}