Question

Write a c++ program to calculate the approximate value of pi using this series. The program takes an input n that determines the number of values we are going to use in this series. Then output the approximation of the value of pi. The more values in the series, the more accurate the data. Note 5 terms isn’t nearly enough. You will try it with numbers read in from a file. to see the accuracy increase. Use a for loop for the calculation and a while loop that allows the user to repeat this calculation for new values n until the user says they want to end the program.

Create an input file with nano lab04bin.txt

12

123

1234

12345

123456

1234567

12345678

123456789

It has to be written in c++

Answer 1

#include <iostream>
#include <iomanip>

using namespace std;

int main() {
   char choice;
   cout << setprecision(12) << endl;
   while(true) {
       int sign = 1;
       double pi = 0;
       cout << "Enter number of terms: ";
       long n;
       cin >> n;
       for(long i = 1; i < n; i += 2) {
           pi += sign/(double)i;
           sign = -sign;
       }
       pi *= 4;
       cout << "value of pi for n = " << n << " is " << pi << endl;
       cout << "Do you want to try again(y or n)? ";
       cin >> choice;
       if(choice == 'n' || choice == 'N') {
           break;
       }
   }
   return 0;
}

Enter number of terms: 50 value of pi forn50 is 3.18157668544 Do you want to try again(y or n)? y Enter number of terms 100 value of pi forn100 is 3.12159465259 Do you want to try again(y or n)? y nter number of terms 1000 value of pi forn1000 is 3.13959265559 Do you want to try again(y or n)? y Enter number of terms:5000000 value of pi forn5000000 is 3.14159225359 Do you want to try again y or n>? rn Process exited after 13.66 seconds with returnvalue 0 Press any key to continue - - -