Đáp án:
Giải thích các bước giải:
\(\begin{array}{l}
B1:DK\left\{ \begin{array}{l}
\sqrt x + 1 \ne 0\\
\sqrt x - 1 \ne 0\\
x > 0
\end{array} \right. \to \left\{ \begin{array}{l}
x \ne 1\\
x > 0
\end{array} \right.\\
\to TXD:x \in \left( {0; + \infty } \right)\backslash \left\{ 1 \right\}\\
B2:\\
DK:\left\{ \begin{array}{l}
\sqrt x - 2 \ne 0\\
\sqrt x - 1 \ne 0\\
x \ge 0
\end{array} \right. \to \left\{ \begin{array}{l}
x \ne 4\\
x \ne 1\\
x \ge 0
\end{array} \right.\\
TXD:x \in \left[ {0; + \infty } \right)\backslash \left\{ {1;4} \right\}\\
B3:\\
a.TXD:x \ne 2\\
b.TXD:x \ne \frac{4}{3}\\
c.TXD:x \ne 1;x \ne 2
\end{array}\)
