3sin2 x+10sin x cos x+3cos2 x=0

3sin2 x+10sin x cos x+3cos2 x=0sin (2x)=x (-3sin (2) /5-3cos (2) /5) 3x sin (2)+5sin (2x)+3x cos (2)=05 sin (2x)+3x (sin (2)+cos (2)=0x=-2,68301x=-1,86266x=0x=1,86266x=2,68301