Fractions sum
Given an integer n, write a method that returns sum of series 1 + (½)² + (⅓)² + ... + (1⁄n)². Do not use library function!
Expected input and output
FractionsSum(3) → 1.36111111111111
FractionsSum(5) → 1.46361111111111
using System;
namespace CSharpExercises.Exercises.Loops
{
class FractionsSumTask
{
static double FractionsSum(int num)
{
double sum = 0.0;
for (int i = 1; i <= num; i++)
{
sum += (1 / (double)(i * i));
}
return sum;
}
static void Main(string[] args)
{
Console.WriteLine(FractionsSum(2)); // 1.25
Console.WriteLine(FractionsSum(7)); // 1.5117970521542
Console.WriteLine(FractionsSum(10)); // 1.54976773116654
}
}
}