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youaremysoul


1,$sin(pi.sin2x) =1$
2,$cos(\dfrac{pi}{2}cos(x - \dfrac{pi}{4})) = \dfrac{\sqrt{2}}{2}$
mn giúp m nha,thank trước hen
2,$cos(\dfrac{pi}{2}cos(x - \dfrac{pi}{4})) = \dfrac{\sqrt{2}}{2}$
mn giúp m nha,thank trước hen