L
longtt1992
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
Bài 1 : [tex]cos^3 x + cos2x + sinx = 0[/tex].
Bài 2 : [tex]cos^5 x + sin^7 x + \frac{1}{2}( cos^3 x + sin^5 x)sin2x = sinx + cosx[/tex]
Bài 2 : [tex]cos^5 x + sin^7 x + \frac{1}{2}( cos^3 x + sin^5 x)sin2x = sinx + cosx[/tex]