truongt3

 Tiếp nè :

6/ $2sin(2x-\frac{\pi}{6})+4sinx+1=0$

7/ $(2sin^{2}x-1)tan^{2}2x+3(2cos^{2}x-1)=0$

8/ $2sin^{2}2x+sin7x-1=sinx$

9/ $cos^{3}x+sin^{3}x+2sin^{2}x=1$

10/ $4sin^{3}x+4sin^{2}x+3sin2x+6cosx=0$.