Решите уравнения а)ctgx+ctg3x-tg2x=0 б)(12sinx-5cosx)(13cos2x-20cosx-11)=362

а)ctgx+ctg3x-tg2x=0

$x=2(\pi n+-tan^{-2}(\sqrt{2+-\sqrt{3}}),$ n Е Z

$x=\frac{1}{2}(4\pi n+- \pi)$ n Е Z

$x=\frac{1}{6}(12 \pi n+-5\pi),$ n Е Z

$x=\frac{1}{6}(12\pi n+-\pi ),$ n Е Z

б)(12sinx-5cosx)(13cos2x-20cosx-11)=362

1/2(-420sin(x)-240sin(2x)+156sin(3x)+45cos(x)+100cos(2x)-65cos(3x)+100)=362

-132sin(x)+100cos^2(x)-65cos(2x)cos(x)+55cos(x)-240sin(x)cos(x)+156sin(x)cos(2x)=362

(20cos(x)-13cos(2x)+11)(5cos(x)-12sin(x))=362