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lan_anh_a


Lại BTVN 
giải pt
[TEX]1./ cos ( 4x/3) = cos^2x[/TEX]
[TEX]2./ 1 + sin(x/2)sinx - cos(x/2) sin^2x = 2 cos^2 ( \frac{\pi}{4} - \frac{x}{2} )[/TEX]
[TEX]3./ 1 + 3tanx = 2sin2x[/TEX]
[TEX]4./ 2cos2x - 8cosx + 7 = \frac{1}{cosx}[/TEX]
[TEX]5./ sin2x(cotx + tanx) = 4 cos^2x[/TEX]
[TEX]6./ 2cos^22x + cos2x = 4 sin^22xcos^2x[/TEX]
[TEX]7./ cos3x - cos 2x =2[/TEX]
[TEX]8./ 4sinx + 2 cosx = 2 + 3 tanx[/TEX]
[TEX]9./ sin2x + 2 tanx = 3 [/TEX]
[TEX]10./ sin^2x + sin^2 3x = 3 cos^22x[/TEX]
[TEX]11./ tan^3(x - \frac{\pi}{4}) = tanx - 1[/TEX]
[TEX]12./ sinx- cos2x = 3sinx + cosx - 2[/TEX]
[TEX]13./ sin2x + cos2x + tanx = 2[/TEX]
[TEX]14./ cos3x - 2 cos2x + cosx = 2[/TEX]
Hi hi , cả bài ko khó + bài ko quá dễ
các bác cùg làm 
--------
@chauhien: sai đâu
giải pt
[TEX]1./ cos ( 4x/3) = cos^2x[/TEX]
[TEX]2./ 1 + sin(x/2)sinx - cos(x/2) sin^2x = 2 cos^2 ( \frac{\pi}{4} - \frac{x}{2} )[/TEX]
[TEX]3./ 1 + 3tanx = 2sin2x[/TEX]
[TEX]4./ 2cos2x - 8cosx + 7 = \frac{1}{cosx}[/TEX]
[TEX]5./ sin2x(cotx + tanx) = 4 cos^2x[/TEX]
[TEX]6./ 2cos^22x + cos2x = 4 sin^22xcos^2x[/TEX]
[TEX]7./ cos3x - cos 2x =2[/TEX]
[TEX]8./ 4sinx + 2 cosx = 2 + 3 tanx[/TEX]
[TEX]9./ sin2x + 2 tanx = 3 [/TEX]
[TEX]10./ sin^2x + sin^2 3x = 3 cos^22x[/TEX]
[TEX]11./ tan^3(x - \frac{\pi}{4}) = tanx - 1[/TEX]
[TEX]12./ sinx- cos2x = 3sinx + cosx - 2[/TEX]
[TEX]13./ sin2x + cos2x + tanx = 2[/TEX]
[TEX]14./ cos3x - 2 cos2x + cosx = 2[/TEX]
Hi hi , cả bài ko khó + bài ko quá dễ
--------
@chauhien: sai đâu
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