#include <cmath>
    double cosh( double arg );

The function cosh() returns the hyperbolic cosine of arg.

C++ also provides the following overloaded forms:

    #include <cmath>
    float cosh( float arg ); // same as coshf() in C99
    long double cosh( long double arg ); // same as coshl() in C99

Related Topics: acos, asin, atan, atan2, cos, sin, sinh, tan, tanh