Question

Tìmn TXĐ của hàm số : a ) \(\frac{x+2}{\left|x\right|-1}\) b) \(\frac{x+1}{\sqrt{x}-1}\)

Answer 1

a.

ĐKXĐ \(\left|x\right|-1\ne0\Leftrightarrow x\ne\pm1\)

\(\Rightarrow D=\left(-\infty;-1\right)\cup\left(-1;1\right)\cup\left(1;+\infty\right)\)

b.

ĐKXĐ: \(\left\{{}\begin{matrix}x\ge0\\\sqrt{x}-1\ne0\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x\ge0\\x\ne1\end{matrix}\right.\)

\(\Rightarrow D=[0;1)\cup\left(1;+\infty\right)\)