Answer to Question #74918 in C++ for Anna

Question

The sum of a series can be computed as sum=x+x^2/2+x^3/3+x^4/4+x^5/5+⋯ ∞<x<∞ stopping when either n terms have been added or when the magnitude of a term in the series is less than 10-6, whichever comes first.
You are required to write a function, sumSeries, which given x, n returns the sum of the series. Use #include <cmath> and the abs function.
Do not use pow.

Answer 1

#include <iostream>
#include <cmath>

using namespace std;

double sumSeries(double, int);

int main()
{
int n;
double x;

cout << "Please enter the value x: " << endl;
cin >> x;

cout << "Please enter the number of terms (n): " << endl;
cin >> n;

cout << "The sum of the series is " << sumSeries(x, n);

return 0;
}

double sumSeries(double x, int n)
{
double xpow = x*x, sum = x;

for(int i = 2; i <= n; ++i)
{
sum += xpow / i;
if(abs(xpow / i - xpow/(x*(i-1))) < 0.000001)
break;
xpow *= x;
}

return sum;
}