от Nathi123 » 19 Мар 2017, 12:12
[tex]4(1 + cosx )sin^{2}\frac{x}{2} = 3sinx\Leftrightarrow 4.2cos^{2}\frac{x}{2}sin^{2}\frac{x}{2} = 3sinx\Leftrightarrow 2sin^{2}x - 3sinx -2 =0[/tex]
[tex]\Leftrightarrow sinx = 2 \cup sinx=-\frac{1}{2}; | sinx |\le 1\Rightarrow sinx=-\frac{1}{2}\Rightarrow x=-\frac{\pi}{6}+2k\pi\cup x = \frac{7\pi}{6}+2k\pi
k\in Z[/tex].