ĐKXĐ: 1-x^2>=0
=>x^2<=1
=>-1<=x<=1
\(\sqrt{1-x^2}=x-1\)
=>\(\left\{{}\begin{matrix}x-1>=0\\1-x^2=\left(x-1\right)^2\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x>=1\\1-x^2=x^2-2x+1\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=1\\-2x^2+2x=0\end{matrix}\right.\)
=>x=1