−2sinθcosθ−1 |
cos2θ−sin2θ |
−(sinθ+cosθ)2 |
(sinθ+cosθ)cosθ−sinθ) |
(sinθ+cosθ) |
(sinθ−cosθ) |
tanθ+1 |
tanθ−1 |
−sinθ−cosθ |
cosθ−sinθ |
−tanθ−1 |
1−tanθ |
tanθ+1 |
tanθ−1 |
右边=
tan(8π+π+θ)+1 |
tanθ−1 |
tanθ+1 |
tanθ−1 |
∴左=右,得证;
(2)左边=
| ||
|
sin2θ |
sinθ(1−cosθ) |
sinθ |
1−cosθ |
右边=
cosθ•(
| ||
sin2θ |
sinθ(1+cosθ) |
1−cos2θ |
sinθ |
1−cosθ |
∴左=右,得证.