30/(sin^2 26º + sin^2 146º + sin^2 94º) =30/((1-cos52)/2+(1+cos112)/2+(1+cos8)/2)=
=30(3/2+(cos8+cos112-cos52)/2)=30/(3/2+(cos8-2sin30sin82)/2)=
=30/(3/2+(cos8-sin82)/2)=30/(3/2)=20

Question

Алгебра: 30/(sin^2 26º + sin^2 146º + sin^2 94º)

maximstrekalovs · Answer

30/(sin^2 26º + sin^2 146º + sin^2 94º)  =30/((1-cos52)/2+(1+cos112)/2+(1+cos8)/2)==30(3/2+(cos8+cos112-cos52)/2)=30/(3/2+(cos8-2sin30sin82)/2)==30/(3/2+(cos8-sin82)/2)=30/(3/2)=20...