Question

2cos^2x+sinx*cosx+1=0

Answer 1

$2cos^2x+sin xcdotcos x+1=0, \ 2cos^2x+sin xcdotcos x+sin^2x+cos^2x=0, \ 3cos^2x+sin xcdotcos x+sin^2x=0, \ 3+frac{sin x}{cos x}+frac{sin^2x}{cos^2x}=0, \ tg^2x+tgx+3=0, \ tgx=a, \ a^2+a+3=0, \ D=-11 textless 0, \ ainvarnothing, \ xinvarnothing.$