Thread: Summation formula

Hello

Prove that the sum of k^2 from k=1 to n is equal to:

(n^3)/3 + (n^2)/2 + n/6

The book provided a hint: k^3 -(k -1)^3 = 3k^2 -3k + 1.
But I don't know how to use it.

Thanks in advance

Write this equation down for and add them.

Then and