Let $f(x)=\log _{\mathrm{e}} x$ and $g(x)=\frac{x^4-2 x^3+3 x^2-2 x+2}{2 x^2-2 x+1}$. Then the domain of $f \circ g$ is
Solution
<p>$$\begin{aligned}
& f(x)=\ln x \\
& g(x)=\frac{x^4-2 x^3+3 x^2-2 x+2}{2 x^2-2 x+1} \\
& D_g \in R \\
& D_f \in(0, \infty)
\end{aligned}$$</p>
<p>For $D_{f o g} \Rightarrow g(x)>0$</p>
<p>$$\begin{aligned}
& \frac{x^4-2 x^3+3 x^2-2 x+2}{2 x^2-2 x+1}>0 \\
& \Rightarrow x^4-2 x^3+3 x^2-2 x+2>0
\end{aligned}$$</p>
<p>Clearly $\mathrm{x}<0$ satisfies which are included in option (1) only.</p>
About this question
Subject: Mathematics · Chapter: Sets, Relations and Functions · Topic: Sets and Operations
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