1. $2sin(x + \frac{\pi}{4}).cos(x - \frac{\pi}{4}) + 2sin(x + \frac{\pi}{4}) + sinx + cosx + \sqrt{2} = 0$
2. $\frac{2sin(2x + \frac{\pi}{3}) + 2sin(x + \frac{\pi}{3})-1}{2cosx - \sqrt{3}} =1$
3. sin3x + (1-cosx).cos2x = (sinx + 2cosx).sin2x
4. $16sinx.cos4x + 1 = \sqrt{3}(tanx + tan2x)+ tanx.tan2x$
- Dahitotn94 yêu thích