| 1 |
| x |
则F′(x)=
| 1 |
| x |
| 1 |
| x2 |
| x−1 |
| x2 |
由F′(x)=
| 1 |
| x |
| 1 |
| x2 |
| x−1 |
| x2 |
F′(x)=
| 1 |
| x |
| 1 |
| x2 |
| x−1 |
| x2 |
(Ⅱ)由题意可知k=F′(x0)=
| x0−a | ||
|
| 1 |
| 2 |
即有x0−
| 1 |
| 2 |
| x | 20 |
| 1 |
| 2 |
| x | 20 |
令t=x0−
| 1 |
| 2 |
| x | 20 |
| 1 |
| 2 |
| x | 20 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 2 |
则a≥
| 1 |
| 2 |
| 1 |
| 2 |
| a |
| x |
| 1 |
| 2 |
| 1 |
| x |
| 1 |
| x |
| 1 |
| x2 |
| x−1 |
| x2 |
| 1 |
| x |
| 1 |
| x2 |
| x−1 |
| x2 |
| 1 |
| x |
| 1 |
| x2 |
| x−1 |
| x2 |
| x0−a | ||
|
| 1 |
| 2 |
| 1 |
| 2 |
| x | 20 |
| 1 |
| 2 |
| x | 20 |
| 1 |
| 2 |
| x | 20 |
| 1 |
| 2 |
| x | 20 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 2 |