Question:
Le $f(\mathrm{x})=\mathrm{x}^{2}, \mathrm{x} \in \mathrm{R}$. For any $\mathrm{A} \subseteq \mathrm{R}$, define $\mathrm{g}(\mathrm{A})=\{\mathrm{x} \in \mathrm{R}, f(\mathrm{x}) \in \mathrm{A}\}$. If $\mathrm{S}=[0,4]$, then which one of the following statements is not true ?
Correct Option: , 3
Solution:
$\mathrm{g}(\mathrm{S})=[-2,2]$
So, $\mathrm{f}(\mathrm{g}(\mathrm{S}))=[0,4]=\mathrm{S}$
And $f(S)=[0,16] \Rightarrow f(g(S) \neq f(S)$
Also, $g(f(S))=[-4,4] \neq g(S)$
So, $g(f(S) \neq S$