| n3(n+ 1) | ||
Wykaż, że n2 + 2n2 + 3n2 + 4n2 + ...... + n3 = | ||
| 2 |
| 1 + n | ||
n2 + 2n2 + 3n2 + ... + n3 = n2(1 + 2 + 3 + 4 + ... + n) = n2 * | * n = | |
| 2 |
| n3(n + 1) | ||
= | = P | |
| 2 |
teraz musze to rozkminić bo nie wiem o co w tym chodzi w ogóle 
| 1+n | n3(n+1) | |||
L = n2(1 + 2 + 3 + ... + n) = n2( | *n) = | |||
| 2 | 2 |
| a1+an | 1+n | |||
Sn = | *n = | *n | ||
| 2 | 2 |