freeCodeCamp Challenge Guide: Problem 6: Sum square difference

Problem 6: Sum square difference


Problem Explanation

  • Sum of first n natural numbers can be calculated by using this formula:

    • sum of n numbers
  • Sum of squares of n natural numbers can be calculated by using this formula:

    • sum of n squares
  • We can calculate the values using the above formula and subtract them to get the result.


Solutions

Solution 1 (Click to Show/Hide)
function sumSquareDifference(n) {
  const sumOfN = (n*(n+1))/2;
  const sumOfNSquare = (n*(n+1)*(2*n+1))/6;
  
  //** is exponentaial operator added in ES7, it's equivalent to Math.pow(num, 2)`
  return (sumOfN ** 2) - sumOfNSquare;
}

Relevant Links

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