public static double cosh (double x)

Returns the hyperbolic cosine of a double value. The hyperbolic cosine of x is defined to be (e^x + e^-x)/2 where e is Euler's number.

Special cases:

• If the argument is NaN, then the result is NaN.
• If the argument is infinite, then the result is positive infinity.
• If the argument is zero, then the result is 1.0.

The computed result must be within 2.5 ulps of the exact result.

Parameters:

x

The number whose hyperbolic cosine is to be returned.

Returns:  The hyperbolic cosine of x.

Since:  1.5