Question

3sin^2x -2sinxcosx -cos^2x=0

Answer 1

$3tg^2x-2tgx-1=0 \ tgx=1 \ tgx=- frac{1}{3} \ \ x= frac{ pi }{4} + pi n \ x=-arctg frac{1}{3} + pi k, \ n,k in Z$