The cosh() function computes the hyperbolic cosine of x.

Upon successful completion, cosh() returns the hyperbolic cosine of x.

If the result would cause an overflow, HUGE_VAL is returned and errno is set to ERANGE.

If x is NaN, NaN is returned.

For exceptional cases, matherr(3M) tabulates the values to be returned as dictated by Standards other than XPG4.

The cosh() function will fail if:

ERANGE

The result would cause an overflow.

An application wishing to check for error situations should set errno to 0 before calling cosh(). If errno is non-zero on return, or the returned value is NaN, an error has occurred.

See attributes(5) for descriptions of the following attributes:

acosh(3M), isnan(3M), matherr(3M), sinh(3M), tanh(3M), attributes(5), standards(5)