Question

Answer 1

a: ĐKXĐ: \(x,y\in R\)

b: ĐKXĐ: \(\left[{}\begin{matrix}x< >1\\y< >-2\end{matrix}\right.\)

Answer 2

\(a,ĐKXĐ:x^2+2y^2+1\ne0\left(luôn.đúng.vì.x^2\ge0,2y^2\ge0,1>0\right)\Leftrightarrow x,y\in R\\ b,\left(x-1\right)^2+\left(y+2\right)^2\ne0\Leftrightarrow\left\{{}\begin{matrix}\left(x-1\right)^2\ne0\\\left(y+2\right)^2\ne0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x-1\ne0\\y+2\ne0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x^2\ne1\\y^2\ne-2\end{matrix}\right.\)