Here you can find the source of cosh(double paramDouble)
public static strictfp double cosh(double paramDouble)
//package com.java2s; //License from project: Open Source License public class Main { public static strictfp double cosh(double paramDouble) /* */{//from w w w . ja v a2s. c om /* 317 */return (StrictMath.exp(paramDouble) + StrictMath .exp(-paramDouble)) * 0.5D; /* */} }