Functions Question 1

Question 1 - 2024 (01 Feb Shift 1)

Let $\mathrm{f}: \mathbf{R} \rightarrow \mathbf{R}$ and $\mathrm{g}: \mathbf{R} \rightarrow \mathbf{R}$ be defined as

$f(x)=\left{\begin{array}{cc}\log _{e} x & , x>0 \ e^{-x} & , \quad x \leq 0\end{array}\right.$ and

nan

(1) one-one but not onto

(2) neither one-one nor onto

(3) onto but not one-one

(4) both one-one and onto

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Answer (2)

Solution

$g(f(x))=\left{\begin{array}{l}f(x), f(x) \geq 0 \ e^{f(x)}, f(x)<0\end{array}\right.$

$\mathrm{g}(\mathrm{f}(\mathrm{x}))=\left{\begin{array}{l}e^{-x},(-\infty, 0] \ e^{\ln x},(0,1) \ \ln x,[1, \infty)\end{array}\right.$

Description of the image

Graph of $g(f(x))$

$\mathrm{g}(\mathrm{f}(\mathrm{x})) \Rightarrow$ Many one into