Решите уравнение 6sin^2x+cos x — 5=0

6sin^2 (x)+cos (x) -5=06 (1-cos^2 (x)+cos (x) -5=06-6cos^2 (x)+cos (x) -5=06cos^2 (x) -cos (x) -1=0cos (x)=t6t^2-t-1=0D=b^2-4ac=1+24=25t1,2=(-b±sqrt (D) /2at1=(1+5) /12=1/2t2=(1-5) /12=-1/3a) cos (x)=1/2 x=±arccos (1/2)+2*pi*n x=±pi/3+2*pi*nб) cos (x)=-1/3 x=arccos (-1/3)+2*pi*n