Question

решить пример
1+2Sin2x+2Cosквадратеx=0

Answer 1

$1+2sin2x+2cos^2x=0\\sin^2x+cos^2x+4sinxcosx+2cos^2x=0|\; :cos^2x\\ tgx^2x+4tgx+3=0\\ tgx=u\\u^2+4u+3=0\\ D: \; 16-12=4\\ u=\frac{-4\pm 2}{2}\\u_1=-1\\tgx=-1\\x=-\frac{\pi}{4}+\pi n, \; n\in Z;\\\\u_2=-3\\tgx=-3\\x=-arctg3+\pi n, \; n\in Z$