1．（2023春•郫都区期末）已知tanα+tanβ=−6\tan \alpha +\tan \beta =-6tanα+tanβ=−6，tan(α+β)=−1\tan (\alpha +\beta )=-1tan(α+β)=−1，则sin(α+β)cos(α−β)=(\frac{\sin (\alpha +\beta )}{\cos (\alpha -\beta )}=(cos(α−β)sin(α+β)=( )))