| cosx |
| 1−x |
所以y′=
| (cosx)′•(1−x)−cosx•(1−x)′ |
| (1−x)2 |
=
| (−sinx)•(1−x)+cosx |
| (1−x)2 |
| cosx−sinx+xsinx |
| (1−x)2 |
故选B.
| cosx |
| 1−x |
| cosx+sinx+xsinx |
| (1−x)2 |
| cosx−sinx+xsinx |
| (1−x)2 |
| cosx−sinx+xsinx |
| 1−x |
| cosx+sinx−xsinx |
| (1−x)2 |
| cosx |
| 1−x |
| (cosx)′•(1−x)−cosx•(1−x)′ |
| (1−x)2 |
| (−sinx)•(1−x)+cosx |
| (1−x)2 |
| cosx−sinx+xsinx |
| (1−x)2 |