Question

упростите выражение -6sin^2x*ctg^2x-4-6sin^2x

Answer 1

$-6sin ^{2} x*ctg ^{2} x-4-6sin ^{2} x= \\ =-6sin ^{2} x* \frac{cos ^{2} x}{sin ^{2} x} -4-6sin ^{2} x= \\ =-6cos ^{2} x-4-6sin ^{2} x \\=-(6cos ^{2} x+6sin ^{2} x+4)=-(6*1+4)=-(6+4)= \\ =-10$