Question

Помогите, пожалуйста! ​

Answer 1

$(Sin\alpha-Cos\alpha )^{2}=Sin^{2}\alpha-2Sin\alpha Cos\alpha+Cos^{2}\alpha =1-2Sin\alpha Cos\alpha =1-2*(-\frac{1}{5})=1+\frac{2}{5}=\frac{7}{5}\\\\Sin\alpha-Cos\alpha=-\sqrt{\frac{7}{5}}=-\frac{\sqrt{35}}{5}\\\\Otvet:\boxed{-\frac{\sqrt{35}}{5}}$