三角恒等变换公式化简: 1.()cos(2)cos 23
f x x x π=--
2. 2()22sin f x x x =-.
3.23
cos sin sin 3)(2-+=x x x x f
4. cos 2()sin()4x f x x π=+
5. x x x f 2sin 262sin 2)(-??
? ??+-=π 6. x x x x f 2cos 3cos sin 2)(+=
7. 22()(sin2cos2)2sin 2f x x x x =+- 8. ()22sin sin()2f x x x x π
=+?+