Question

СОС помогите решить б или 6 помогите

Answer 1

sinαcosβ+cosαsinβ-2sinαcosβ=cosαsinβ-sinαcosβ=-sin(α-β)=-sin(34-64)=sin30=1/2
-14cos2α=-14(1-2sin²α)=28sin²α-14=28*0,49-14=13,72-14=-0,28

Answer 2

$1)sin( \alpha + \beta )=-2sin \alpha cos \beta =sin \alpha cos \beta +cos \alpha sin \beta- \\ -2sin \alpha cos \beta =cos \alpha sin \beta- sin \alpha cos \beta = -sin( \alpha - \beta )= \\ =-sin(34-64)=-sin(-30)=sin30= \frac{1}{2} \\ \\ 2)-14cos2 \alpha \\ cos2 \alpha =cos ^{2} \alpha -sin ^{2} \alpha =1-sin ^{2} \alpha -sin ^{2} \alpha =1-2sin ^{2} \alpha \\sina=-0.7 \\ \\ -14cos2a=-14(1-2sin ^{2} \alpha )=-14(1-2*(-0.7) ^{2} ) =\\ =-14*(1-2*0.49)=-14*(1-0.98)=-14*0.02=-0.28$