Create a program to calculate an approximation for PI using the expression

pi/4 = 1/1 - 1/3 + 1/5 -1/7 + 1/9 - 1/11 + 1/13 ...

The user will indicate how many terms must be used, and the program will display all the results until that amount of terms.

Solution

using System; public class Speed{ public static void Main(){ int terms; double result = 0; Console.WriteLine("PI estimator!"); Console.Write("Enter the amount of terms to test: "); terms = Convert.ToInt32(Console.ReadLine()); for (int i=1; i<=terms; i++) { int divisor = 2*i - 1; if (i%2 == 1) // Odd term: positive result += 1.0f/divisor; else // Even term: negative result -= 1.0f/divisor; Console.WriteLine("To term {0}: {1}", i, 4*result); } } }