Lời giải:
a)
ĐKXĐ: \(\left\{\begin{matrix} x^2-3\geq 0\\ 1-\sqrt{x^2-3}\neq 0\end{matrix}\right.\Leftrightarrow \left\{\begin{matrix} x^2-3\geq 0\\ x^2-3\neq 1\end{matrix}\right.\)
\(\Leftrightarrow \left\{\begin{matrix} \left[\begin{matrix} x\geq \sqrt{3}\\ x\leq -\sqrt{3}\end{matrix}\right.\\ x^2\neq 4\end{matrix}\right.\Leftrightarrow \left\{\begin{matrix} \left[\begin{matrix} x\geq \sqrt{3}\\ x\leq -\sqrt{3}\end{matrix}\right.\\ x\neq \pm 2\end{matrix}\right.\)
\(\Leftrightarrow \left[\begin{matrix} x\geq \sqrt{3}, x\neq 2\\ x\leq -\sqrt{3}, x\neq -2\end{matrix}\right.\)
b)
ĐKXĐ: \(\left\{\begin{matrix} 3x+1\geq 0\\ 2-\sqrt{3x+1}\neq 0\end{matrix}\right.\Leftrightarrow \left\{\begin{matrix} 3x+1\geq 0\\ 3x+1\neq 4\end{matrix}\right.\Leftrightarrow \left\{\begin{matrix} x\geq \frac{-1}{3}\\ x\neq 1\end{matrix}\right.\)
