Verified answer

Verified answer

Ответ:

Объяснение:

(соsα/(1+sinα)+cosα/(1-sinα))*sin(2α)=

=((cosα*(1-sinα)+cosα*(1+sinα))/((1+sinα)*(1-sinα)))*sin(2α)=

=((cosα-sinα*cosα+cosα+sinα*cosα)/(1-sin²α))*sin(2α)=

=(2*cosα/cos²α)*sin(2α)=(2/cosα)*2*sinα*cosα=4*sinα.