[sinα+cos(α+β)sinβ]*cos(α+β)=sinαcos(α+β)+(1-(sin(α+β))^2)sinβ=(1/2)(sin(2α+β)-sinβ)+sinβ-(sin(α+β))^2 *sinβ=(1/2)(sin(2α+β)+sinβ)-(sin(α+β))^2 *sinβ=sin(α+β)cosα-(sin(α+...