Calculate the algebraic expression in C#

Question

Calculate the algebraic expression Z, for which n is inputted by user. Use 2 for loops to solve the problem.

My code so far:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {

            int n, k = 1;
            double z;
            float sum, p;
            n = Console.Read();

            for (int i = 0; i < n; i+=2)
            {
                sum += p;

                for (int j = 0; j < n; j++)
                {
                    p *= (3 * k + 2);
                }

            }

        }
    }
}

I'm totally stack in the for loops... any help is appreciated.

Answer 1

• p has to be initialized to 1 as 0 * X == 0
• Also i and j (why not k) have to be initialized to 1 as it is required by your formula
• You have to sum up the products after the products where calculated as you would add 1 to the correct result otherwise and you would not add the last calculated product

So the code below should give the correct result:

        float sum = 0;

        int n = Console.Read();

        for (int i = 1; i <= n; i++)
        {

          float p = 1;
          for (int k = 1; k <= i+2; k++)
          {
            p *= (3 * k + 2);
          }              

          sum += p;
        }