Question

Срочно помогите пожалуйста

Answer 1

$displaystyle tt sin^2: alphacdot ctg^2: alpha div(1-sin^2: alpha)=sin^2: alphacdot ctg^2: alpha div cos^2: alpha=(sin: alpha cdot ctg: alpha div cos: alpha)^2=(sin: alpha cdot frac{cos: alpha}{sin: alpha}cdot frac{1}{cos: alpha})^2=1^2=boxed{bold{1}}$

Answer 2

=sin²x ctg² x : cos²x

=(sin x ctg x: cos x)²

= (sin x * sinx/cosx * 1/cosx)²

=1²=1