

câu b
[tex]3tanx-\frac{3}{cos2x}-\frac{2tanx-2}{1+tanx}+4cos^{2}x=2[/tex]
câu c:
[tex]2cos^{2}x+3cosx-2cos3x=4sinx.sin2x[/tex]
[tex]3tanx-\frac{3}{cos2x}-\frac{2tanx-2}{1+tanx}+4cos^{2}x=2[/tex]
câu c:
[tex]2cos^{2}x+3cosx-2cos3x=4sinx.sin2x[/tex]