Here you can find the source of tanh(double paramDouble)
public static strictfp double tanh(double paramDouble)
//package com.java2s; //License from project: Open Source License public class Main { public static strictfp double tanh(double paramDouble) /* */{/*from w w w. j ava2 s .c om*/ /* 330 */return sinh(paramDouble) / cosh(paramDouble); /* */} public static strictfp double sinh(double paramDouble) /* */{ /* 304 */return (StrictMath.exp(paramDouble) - StrictMath .exp(-paramDouble)) * 0.5D; /* */} public static strictfp double cosh(double paramDouble) /* */{ /* 317 */return (StrictMath.exp(paramDouble) + StrictMath .exp(-paramDouble)) * 0.5D; /* */} }