| 1 | 1 | 1 | 1 | |||||
x= | + | + | +...+ | |||||
| 2*4 | 4*6 | 6*8 | 98*100 |
| 1 | 1 | 1 | 1 | 1 | |||||
*[ | + | + | +...............+ | ]= | |||||
| 2*2 | 1*2 | 2*3 | 3*4 | 49*50 |
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |||||||||||
= | *{ | − | + | − | + | − | +....− | + | − | ]= | ||||||||||
| 4 | 1 | 2 | 2 | 3 | 3 | 4 | 49 | 49 | 50 |
| 1 | 1 | 1 | 49 | |||||
= | *[1− | ]= | * | = | ||||
| 4 | 50 | 4 | 50 |
| 49 | ||
= | ||
| 200 |
wiem że to jest sobie równe ale jak wpaść na takie coś?
| 1 | 1 | 1 | |||
= | − | ||||
| n*(n+1) | n | n+1 |
