C# | Math.Cos() Method Last Updated : 11 Jan, 2022 Comments Improve Suggest changes Like Article Like Report Math.Cos() is an inbuilt Math class method which returns the cosine of a given double value argument(specified angle).Syntax: public static double Cos(double num) Parameter: num: It is the angle(measured in radian) whose cosine is to be returned and the type of this parameter is System.Double. Return Value: Returns the cosine of num of type System.Double. If num is equal to NegativeInfinity, PositiveInfinity, or NaN, then this method returns NaN.Below are the programs to illustrate the Math.Cos() method.Program 1: To show the working of Math.Cos() method. CSharp // C# program to demonstrate working // Math.Cos() method using System; class Geeks { // Main Method public static void Main(String []args) { double a = 70; // converting value to radians double b = (a * (Math.PI)) / 180; // using method and displaying result Console.WriteLine(Math.Cos(b)); a = 50; // converting value to radians b = (a * (Math.PI)) / 180; // using method and displaying result Console.WriteLine(Math.Cos(b)); a = 73; // converting value to radians b = (a * (Math.PI)) / 180; // using method and displaying result Console.WriteLine(Math.Cos(b)); a = 77; // converting value to radians b = (a * (Math.PI)) / 180; // using method and displaying result Console.WriteLine(Math.Cos(b)); } } Output: 0.342020143325669 0.642787609686539 0.292371704722737 0.224951054343865 Program 2: To show the working of Math.Cos() method when the argument is NaN or infinity. CSharp // C# program to demonstrate working // Math.Cos() method in infinity case using System; class Geeks { // Main Method public static void Main(String []args) { double positiveInfinity = Double.PositiveInfinity; double negativeInfinity = Double.NegativeInfinity; double nan = Double.NaN; double result; // Here argument is negative infinity, // output will be NaN result = Math.Cos(negativeInfinity); Console.WriteLine(result); // Here argument is positive infinity, // output will also be NaN result = Math.Cos(positiveInfinity); Console.WriteLine(result); // Here argument is NaN, output will be NaN result = Math.Cos(nan); Console.WriteLine(result); } } Output: NaN NaN NaN Create Quiz Comment K Kirti_Mangal Follow 0 Improve K Kirti_Mangal Follow 0 Improve Article Tags : Misc C# CSharp-method CSharp-Math Explore IntroductionC# Tutorial 2 min read Introduction to .NET Framework 6 min read C# .NET Framework (Basic Architecture and Component Stack) 6 min read C# Hello World 2 min read Common Language Runtime (CLR) in C# 4 min read FundamentalsC# Identifiers 2 min read Data Types in C# 6 min read C# Variables 4 min read C# Literals 5 min read Operators in C# 7 min read C# Keywords 5 min read Control StatementsC# Decision Making (if, if-else, if-else-if ladder, nested if, switch, nested switch) 5 min read C# Switch Statement 4 min read Loops in C# 4 min read C# Jump Statements (Break, Continue, Goto, Return and Throw) 4 min read OOP ConceptsClass and Objects in C# 4 min read Constructors in C# 5 min read C# Inheritance 3 min read Encapsulation in C# 2 min read C# Abstraction 4 min read MethodsMethods in C# 4 min read Method Overloading in C# 4 min read Method Parameters in C# 4 min read Method Overriding in C# 7 min read Anonymous Method in C# 2 min read ArraysArrays in C# 6 min read Jagged Arrays in C# 4 min read Array Class in C# 5 min read How to Sort an Array in C# | Array.Sort() Method Set - 1 8 min read How to find the rank of an array in C# 2 min read ArrayListArrayList in C# 6 min read ArrayList Class in C# 4 min read C# | Array vs ArrayList 2 min read StringStrings in C# 6 min read C# Verbatim String Literal - @ 5 min read C# String Class 9 min read C# StringBuilder 2 min read C# String vs StringBuilder 3 min read TupleC# Tuple 7 min read C# Tuple Class 3 min read C# ValueTuple 7 min read C# ValueTuple Struct 4 min read IndexersC# Indexers 5 min read C# Multidimensional Indexers 5 min read C# - Overloading of Indexers 3 min read Like