Here you can find the source of acos(Integer a)
public static double acos(Integer a)
//package com.java2s; /*//from w w w .ja v a 2 s.c o m * Licensed to Elasticsearch under one or more contributor * license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright * ownership. Elasticsearch 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 { public static double acos(Short a) { return Math.acos(a.doubleValue()); } public static double acos(Integer a) { return Math.acos(a.doubleValue()); } public static double acos(Float a) { return Math.acos(a.doubleValue()); } public static double acos(Long a) { return Math.acos(a.doubleValue()); } public static double acos(Double a) { return Math.acos(a); } }