;)
zosia: Ciąg (an)okreslony jest wzorem an=n−(−1)nn. suma trzech poczatkowych wyrazow tego
ciagu jest rowna
a)7
b)656
c)356
d)6
22 lut 16:02
Trivial:
S3 = a1 + a2 + a3 = ...
22 lut 16:07
zosia: 6?
22 lut 16:15
zosia: 6?
22 lut 16:15
Trivial:
| | (−1)1 | |
a1 = 1− |
| = 1+1 = 2. |
| | 1 | |
| | (−1)2 | | 1 | | 1 | |
a2 = 2− |
| = 2− |
| = 1 |
| . |
| | 2 | | 2 | | 2 | |
| | (−1)3 | | 1 | | 1 | |
a3 = 3− |
| = 3+ |
| = 3 |
| . |
| | 3 | | 3 | | 3 | |
| | 1 | | 1 | | 1 | | 1 | | 3 | | 2 | | 5 | |
S3 = 2 + 1 |
| + 3 |
| = 6 + |
| + |
| = 6 + |
| + |
| = 6 |
| . |
| | 2 | | 3 | | 2 | | 3 | | 6 | | 6 | | 6 | |
22 lut 16:40