Question

sinα*cosα , если sinα-cosα=√2

Answer 1

$Sin alpha -Cos alpha = sqrt{2}\\(Sin alpha -Cos alpha ) ^{2} =( sqrt{2} ) ^{2}\\Sin ^{2} alpha -2Sin alpha Cos alpha +Cos ^{2} alpha =2 \\1-2Sin alpha Cos alpha =2\\2Sin alpha Cos alpha =-1\\Sin alpha Cos alpha =- frac{1}{2}$