[TEX]sin^82x+cos^82x=\frac{41}{128}[/TEX]
[TEX](sin^42x+cos^42x)^2-2.cos^42x.sin^42x=\frac{41}{128}[/TEX]
[TEX](1-2.cos^22x.sin^22x)^2-2.cos^42x.sin^42x=\frac{41}{128}[/TEX]
[TEX]1-4.sin^22x.cos^22x+4.sin^42x.cos^42x-2.cos^42x.sin^42x=\frac{41}{128}[/TEX]
[TEX]2.sin^42x.cos^42x-4.sin^22x.cos^22x+1=\frac{41}{128}[/TEX]
[TEX]2.sin^42x.cos^42x-4.sin^22x.cos^22x+\frac{87}{128}=0[/TEX]
[TEX]16.sin^42x.cos^42x-32.sin^22x.cos^22x+\frac{87}{16}=0[/TEX]
[TEX]sin^44x-8.sin^24x+\frac{87}{16}=0[/TEX]
đặt [TEX]sin^24x=t (0 \leq t \leq 1)[/TEX]
[TEX]t^2-8.t+\frac{87}{16}=0[/TEX]
[TEX]t=\frac{3}{4}(T/M)[/TEX]
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[TEX]sin^{10}x+cos^{10}x=\frac{29}{64}[/TEX]
[TEX](sin^5x+cos^5x)^2-2.sin^5x.cos^5x=\frac{29}{64}[/TEX]
[TEX](sin^3x-sin^3x.cos^2x+cos^3x-cos^3x.sin^2x)^2-2.sin^5x.cos^5x=\frac{29}{64}[/TEX]
[TEX][(sinx+cosx).(1-sinx.cosx)-sin^2x.cos^2x.(sinx+cosx)]^2-2.sin^5x.cos^5x=\frac{29}{64}[/TEX]
[TEX][(sinx+cosx).(1-sinx.cosx-sin^2x.cos^2x)]^2-2.sin^5x.cos^5x=\frac{29}{64}[/TEX]
[TEX]sinx+cosx=t ( - \sqrt{2} \leq t \leq \sqrt{2})[/TEX]
[TEX]sinx.cosx=\frac{t^2-1}{2}[/TEX]
[TẶNG BẠN] TRỌN BỘ Bí kíp học tốt 08 môn
