3sin^2 x+3sin2x-2 =5cos2x СРОЧНО!

Question

3sin^2 x+3sin2x-2 =5cos2x СРОЧНО!

Answer 1

3sin²x+6sinxcosx-2sin²x-2cos²x-5cos²x+5sin²x=0/cos²x
6tg²x+6tgx-7=0
tgx=a
6a²+6a-7=0
D=36+168=204
a1=(-6-2√51)/12=-1/2-√51/6⇒tgx=-1/2-√51/6⇒x=-arctg(1/2+√51/6)+πn,n∈z
a2=-1/2+√51/6⇒tgx=-1/2+√61/6⇒x=arctg(√51/6-1/2)+πk,k∈z