Question Detail
Question
Prove by induction that 1² + 2² + 3² + ... + n² = n(n+1)(2n+1)/6 for n≥1 and find sum of squares of first 20 integers.
Correct Answer
Option A is the correct answer.
Detailed Explanation
Use formula S_n = n(n+1)(2n+1)/6 → 20×21×41/6=2870.
Hint
Apply the proven formula.