Tìm điều kiện xác định của phân giác: a, x^2-4/x^2-1 b, 2/(x+1)(x-3) c, 2x+1/x^2-5+6 d, 2x+3/4x-5 e, x^2-1/x^2-2x+1 02/09/2021 Bởi Emery Tìm điều kiện xác định của phân giác: a, x^2-4/x^2-1 b, 2/(x+1)(x-3) c, 2x+1/x^2-5+6 d, 2x+3/4x-5 e, x^2-1/x^2-2x+1
Giải thích các bước giải: \[\begin{array}{l}a,\frac{{{x^2} – 4}}{{{x^2} – 1}}\\ \Rightarrow {x^2} – 1 \ne 0 \Leftrightarrow \left( {x – 1} \right)\left( {x + 1} \right) \ne 0 \Rightarrow \left\{ \begin{array}{l}x \ne 1\\x \ne – 1\end{array} \right.\\b,\\\frac{2}{{\left( {x + 1} \right)\left( {x – 3} \right)}}\\ \Rightarrow \left( {x + 1} \right)\left( {x – 3} \right) \ne 0 \Rightarrow \left\{ \begin{array}{l}x \ne – 1\\x \ne 3\end{array} \right.\\c,\\\frac{{2x + 1}}{{{x^2} – 5x + 6}}\\ \Rightarrow {x^2} – 5x + 6 \ne 0 \Leftrightarrow \left( {x – 2} \right)\left( {x – 3} \right) \ne 0\\ \Leftrightarrow \left\{ \begin{array}{l}x \ne 2\\x \ne 3\end{array} \right.\\d,\\\frac{{2x + 3}}{{4x – 5}} \Rightarrow 4x – 5 \ne 0 \Leftrightarrow x \ne \frac{5}{4}\\e,\\\frac{{{x^2} – 1}}{{{x^2} – 2x + 1}} \to {x^2} – 2x + 1 \ne 0 \Leftrightarrow {\left( {x – 1} \right)^2} \ne 0 \Leftrightarrow x \ne 1\end{array}\] Bình luận
Giải thích các bước giải:
\[\begin{array}{l}
a,\frac{{{x^2} – 4}}{{{x^2} – 1}}\\
\Rightarrow {x^2} – 1 \ne 0 \Leftrightarrow \left( {x – 1} \right)\left( {x + 1} \right) \ne 0 \Rightarrow \left\{ \begin{array}{l}
x \ne 1\\
x \ne – 1
\end{array} \right.\\
b,\\
\frac{2}{{\left( {x + 1} \right)\left( {x – 3} \right)}}\\
\Rightarrow \left( {x + 1} \right)\left( {x – 3} \right) \ne 0 \Rightarrow \left\{ \begin{array}{l}
x \ne – 1\\
x \ne 3
\end{array} \right.\\
c,\\
\frac{{2x + 1}}{{{x^2} – 5x + 6}}\\
\Rightarrow {x^2} – 5x + 6 \ne 0 \Leftrightarrow \left( {x – 2} \right)\left( {x – 3} \right) \ne 0\\
\Leftrightarrow \left\{ \begin{array}{l}
x \ne 2\\
x \ne 3
\end{array} \right.\\
d,\\
\frac{{2x + 3}}{{4x – 5}} \Rightarrow 4x – 5 \ne 0 \Leftrightarrow x \ne \frac{5}{4}\\
e,\\
\frac{{{x^2} – 1}}{{{x^2} – 2x + 1}} \to {x^2} – 2x + 1 \ne 0 \Leftrightarrow {\left( {x – 1} \right)^2} \ne 0 \Leftrightarrow x \ne 1
\end{array}\]