Java tutorial
import java.io.File; /* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * */ public class Main { /** * Returns the <a href="http://mathworld.wolfram.com/HyperbolicCosine.html"> * hyperbolic cosine</a> of x. * * @param x double value for which to find the hyperbolic cosine * @return hyperbolic cosine of x */ public static double cosh(double x) { return (Math.exp(x) + Math.exp(-x)) / 2.0; } }