Solve `1-x=sqrt(x^2-2+1.)`

Explanation

`1-x=sqrt(x^2-2x +1)`
or `1-x= sqrt(x^2-2x+1)`
or `1-x = sqrt((x-1)^2`
or ` 1-x = | x-1|`
or `rArr 1-x ge 0 `
`or x le 1`