P
prince_internet
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
BT1:
[TEX]2(Cos^2x + \frac{4}{Cos^2x}) + 9(\frac{2}{Cosx} - Cosx) - 1 = 0[/TEX]
BT2:
[TEX]5(Sinx + Cosx) + Sin3x - Cos3x = 2\sqrt{2} (2 + Sin2x)[/TEX]
BT3:
[TEX](2Sinx - 1)(2Cos2x + Sin2x + 1) = 3 - 4Cos^2x[/TEX]
[TEX]2(Cos^2x + \frac{4}{Cos^2x}) + 9(\frac{2}{Cosx} - Cosx) - 1 = 0[/TEX]
BT2:
[TEX]5(Sinx + Cosx) + Sin3x - Cos3x = 2\sqrt{2} (2 + Sin2x)[/TEX]
BT3:
[TEX](2Sinx - 1)(2Cos2x + Sin2x + 1) = 3 - 4Cos^2x[/TEX]