orld.wolfram.com/HyperbolicCosine.html" TARGET="_top"> hyperbolic cosine of this complex number. Implements the formula:
cosh(a + bi) = cosh(a)cos(b) + sinh(a)sin(b)i}
where the (real) functions on the right-hand side are {@link FastMath#sin}, {@link FastMath#cos}, {@link FastMath#cosh} and {@link FastMath#sinh}.
Returns {@link Complex#NaN} if either real or imaginary part of theinput argument is {@code NaN}.
Infinite values in real or imaginary parts of the input may result in infinite or NaN values returned in parts of the result.
Examples: cosh(1 ± INFINITY i) = NaN + NaN i cosh(±INFINITY + i) = INFINITY ± INFINITY i cosh(±INFINITY ± INFINITY i) = NaN + NaN i
@return the hyperbolic cosine of this complex number.
@since 1.2