I need to write a program/function which calculates the series sum according to the formula:

The data that the user types is: **m**.

I am a total beginner and I have no idea how to do it… I am assuming that I need to create a loop (or 2)… but how…? So I would be very grateful if someone could help me.

## Answer

The symbol Σ (sigma) is generally used to denote a sum of multiple terms. In that way you have to sum all (1+j) / (2*j**3 + 3) for every j from 0 to m.

**As you see bellow, m is equal to 14, but you can change this parameter.**

#include <iostream> #include <math.h> using namespace std; int main() { float s = 0; int m = 14; for(int j = 0; j <= m; j++) s += (1 + j) / (pow(j, 3) + 3); cout << s; return 0; }

**And if you need to take a user input you are welcome as well**

#include <iostream> #include <math.h> using namespace std; int main() { float s = 0; int m; cin >> m; for(int j = 0; j <= m; j++) s += (1 + j) / (pow(j, 3) + 3); cout << s; return 0; }

**Using multiplication instead of pow function**

#include <iostream> using namespace std; int main() { float s = 0; int m; cin >> m; for(int j = 0; j <= m; j++) s += (float)(1 + j) / (j*j*j + 3); cout << s; return 0; }