Question

1 la puterea 2 plus 2 la puterea 2 plus 3 la puterea 2 plus puncte puncte n la 2​

Answer 1

${1}^{2} + {2}^{2} + {3}^{2} + ... + {n}^{2} =$

$= \frac{n(n + 1)(2n + 1)}{6}$