Sopel38: | (n−3)!(n−2)(n−1)n | | (n−4)! (n−3)(n−2)(n−1)n | |
| + |
| < |
| (n−3)! * 6 | | (n−4)! * 24 | |
| | (n−2)!(n−1)n(n+1) | |
|
| / *24 |
| | (n−2)! * 6 | |
4(n−2)(n−1)n + (n−3)(n−2)(n−1)n < 4(n−1)n(n+1)
wymnóż:
n
4 − 6n
3 − n
2 + 6n < 0
n(n
3 − 6n
2 − n + 6) < 0
n[n
2(n−6)−(n−6)] < 0
n[ (n−6)(n
2 −1)] < 0
n(n−6)(n−1)(n+1)<0
n
1 = 0
n
2 = 6
n
3 = 1
n
4 = −1