L
likenike


Giúp mình nha mấy bạn
1. $sin^2 (5x+ \dfrac{2\pi}{5}) = cos^2 (\dfrac{x}{4}+\pi)$
2. $cos2x + sin ( 2x+\dfrac{\pi}{3} ) +sin (2x-\dfrac{\pi}{3}) =\sqrt{2}.sin(x-\dfrac{\pi}{3})$.
1. $sin^2 (5x+ \dfrac{2\pi}{5}) = cos^2 (\dfrac{x}{4}+\pi)$
2. $cos2x + sin ( 2x+\dfrac{\pi}{3} ) +sin (2x-\dfrac{\pi}{3}) =\sqrt{2}.sin(x-\dfrac{\pi}{3})$.
Last edited by a moderator: