(-сos2a+sin2a)/(cos2a)=tg2a-1
(cos^2a+cos^2asina)/(1+sina)=cos^2a=3/4
3sin^2a+(1-sin^2a)^2=3sin^2a+sin^4a-2sin^2a+1=1+sin^2a+sin^4a
=1
(3sin^2a-2)/cosa(3sina+cosa)
sin^2a+sin^2b-sin^asin^2b+1-sin^2a-sin^2b+sin^2asin^2b=1
(-сos2a+sin2a)/(cos2a)=tg2a-1
(cos^2a+cos^2asina)/(1+sina)=cos^2a=3/4
3sin^2a+(1-sin^2a)^2=3sin^2a+sin^4a-2sin^2a+1=1+sin^2a+sin^4a
=1
(3sin^2a-2)/cosa(3sina+cosa)
sin^2a+sin^2b-sin^asin^2b+1-sin^2a-sin^2b+sin^2asin^2b=1