№1 и № 3 очень прошу помочь
1) 3^(2log(9)12)=3^(log(3)12)=12; 3) sinα/(1+cosα)+(1+cosα)/sinα=(sin²α+(1+cosα)²)/(sinα(1+cosα))= =(sin²α+1+cos²α+2cosα)/(sin²α(1+cosα))=(2+2cosα)/(sinα(1+cosα)= =(2(1+cosα))/(sinα(1+cosα))=2/sinα.