Question

Помогите пожалуйста разобраться!!!

Answer 1

(2+3sin^2(a))/(5-3(1-sin^2(a))=
(2+3sin^2(a))/(2+3sin^2(a))=1
1-sin^2(a)=cos^2(a)

Answer 2

$\frac{2+3Sin ^{2} \alpha }{5-3Cos ^{2} \alpha }-Sin ^{2} \alpha = \frac{2Sin ^{2} \alpha +2Cos ^{2} \alpha +3Sin ^{2} \alpha }{5Sin ^{2} \alpha +5Cos ^{2} \alpha -3Cos ^{2} \alpha }-Sin ^{2} \alpha = \frac{5Sin ^{2} \alpha +2Cos ^{2} \alpha }{5Sin ^{2} \alpha +2Cos ^{2} \alpha }$$-Sin ^{2} \alpha =1-Sin ^{2} \alpha =Cos ^{2} \alpha$