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nhoc_smile97


CM các bất đẳng thức sau:
1) sin3x cosx - cos3x sinx - cos2x \leq [TEX]\sqrt2[/TEX]
2) cosx cos3x - sin2x sin4x \leq 1
1) sin3x cosx - cos3x sinx - cos2x \leq [TEX]\sqrt2[/TEX]
2) cosx cos3x - sin2x sin4x \leq 1