S
snowangel1103


1/ $cos^2(x+\frac{4\pi}{3})+cos^2(x+\frac{5\pi}{3})= \frac{1}{2} [cos(\frac{9\pi}{2}-x)+1]$
2/ $\frac{4\sqrt{3}sinx.cos^2x-2cos\frac{5x}{2}cos\frac{x}{2}+\sqrt{3}sin2x+3cosx+2}{2sinx-\sqrt{3}}=0$
2/ $\frac{4\sqrt{3}sinx.cos^2x-2cos\frac{5x}{2}cos\frac{x}{2}+\sqrt{3}sin2x+3cosx+2}{2sinx-\sqrt{3}}=0$