Q
quangnhatkut3


[TEX]1, 4sin^{3}x +3cos^{3}x - 3sinx - sin^{2}x.cosx = 0[/TEX]
[TEX]2, sin^{6}x + cos^{6}x = 2(sin^{8}x + cos^{8}x )[/TEX]
[TEX]3, cosx.cos2x.cos4x.cos8x = \frac{1}{16}[/TEX]
[TEX]2, sin^{6}x + cos^{6}x = 2(sin^{8}x + cos^{8}x )[/TEX]
[TEX]3, cosx.cos2x.cos4x.cos8x = \frac{1}{16}[/TEX]