JEE Main 2026 Mathematics question
If , then is equal to .
Answer: 91
Solution
= 6k³ − 6(k − 1)³ = 6(3k² − 3k + 1), so − = 36k. The sum is Σk² for k = 1..6 = 91.
If , then is equal to .
= 6k³ − 6(k − 1)³ = 6(3k² − 3k + 1), so − = 36k. The sum is Σk² for k = 1..6 = 91.