If $g(x)$ is the inverse of the function $f(x)$ and $f^{\prime}(x)=\frac{1}{h(x)}$, then $g^{\prime}(x)=$
If $g(x)$ is the inverse of the function $f(x)$ and $f^{\prime}(x)=\frac{1}{h(x)}$, then $g^{\prime}(x)=$
- $h(g(x))$
- $\mathrm{g}(\mathrm{h}(\mathrm{x}))$
- $h^{\prime}(f(x))$
- $f(h(x))$
Solution
Given $g(x)$ is inverse of the function $f(x) \& f^{\prime}(x)$
$=\frac{1}{\mathrm{~h}(\mathrm{x})}$
Now, $g(x)=f^{-1}(x) \Rightarrow f(g(x))=x$
Differentiating w.r. to $x$.
$\begin{aligned}
& \mathrm{f}^{\prime}(\mathrm{g}(\mathrm{x})) \cdot \mathrm{g}^{\prime}(\mathrm{x})=1 \Rightarrow \mathrm{g}^{\prime}(\mathrm{x})=\frac{1}{\mathrm{f}^{\prime}(\mathrm{g}(\mathrm{x}))} \\
& =\frac{1}{(1 / \mathrm{h}(\mathrm{g}(\mathrm{x})))}=\mathrm{h}(\mathrm{g}(\mathrm{x}))
\end{aligned}$
Asked in: AP EAMCET 2023 (16 May Shift 2)
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