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

Question

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

Answer 1

3sin^2x + sinxcosx - 2cos^2x = 0  Делим на cos^2x

3tg^2x+tgx-2=0

D=1+24=25

tgx=2/3  ->x=arctg2/3 + pi*l

tgx= -1  ->x=-pi/4+pi*k