Antwort
$\sum_{k=1}^n k^2 = \frac{n(n + 1)(2n + 1)}{6}$.
Erklärung
Similarly, $\sum_{k=1}^n k = \frac{n(n + 1)}{2}$ and $\sum_{k=1}^n k^3 = \left[\frac{n(n + 1)}{2}\right]^2$. These identities frequently appear in sequence problems.
Start / Bibliothek / CSAT (Suneung) essentials: original practice / Synthetische Lernkarte
In CSAT Mathematics, how is the summation formula $\sum_{k=1}^n k^2$ calculated?
Lernkarte aus dem Deck CSAT (Suneung) essentials: original practice.