Ребята выручайте, срочно!!! 4sin(x + 60°) cosX = ctg1290°

$4sin(x+60к)*cosx=ctg1290к$
$4cos(\frac{\pi }{6}-x)*cosx= \sqrt{3}$
$cos(\frac{\pi }{6}-x)*cosx= \frac{ \sqrt{3} }{4}$
$\frac{1}{4}(\sqrt{3}+2cos(\frac{\pi}{6}-2x))= \frac{ \sqrt{3} }{4}$
$\sqrt{3} +2cos(\frac{\pi}{6}-2x)= \sqrt{3}$
$2cos(\frac{\pi}{6}-2x)= \sqrt{3} - \sqrt{3}$
$cos(\frac{\pi}{6}-2x)= \frac{ \sqrt{3} }{2} - \frac{ \sqrt{3} }{2}$
$\frac{\pi}{6}-2x= \frac{ \pi }{2}+ \pi n$ ; n∈Z
$-2x= \frac{ \pi }{3} + \pi n$ ; n∈Z
$x=- \frac{ \pi }{6} - \frac{ \pi n}{2}$ ; n∈Z ----Ответ