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Q. Match the entries of Column-I with one or more than one entries of column-II. Note that $[x],\{x\}$ and sgn $x$ denote largest integer less than or equal to $x$, fractional part of $x$ and signum function of $x$ respectively.
Column I Column II
A Let $f:[-1,1] \rightarrow R$ be defined by $f(x)=\sqrt[5]{x}+\sin ^{-1} x$ then $f(x)$ is P Odd
B Let $f: R \rightarrow\{-1,0,1\}$ be defined by $f(x)=\operatorname{sgn}\left(\frac{1-|x|}{1+|x|}\right)$ then $f(x)$ is Q Even
C Let $f:[-4,2] \rightarrow[0,3]$ be defined by $f(x)=\sqrt{8-2 x-x^2}$ then $f(x)$ is R Onto
D Let $f :(-\infty, 0] \rightarrow[0, \infty)$ be defined by $f(x)=\frac{2^{-[x]}}{2^{[x]}}-2^{|x|}$ then $f(x)$ is S One-One
T Many-One

Inverse Trigonometric Functions

Solution:

(A) We have
$f(x)=\sqrt[5]{x}+\sin ^{-1} x$
Cleary, domain of $f(x)=[-1,1]$.
Also, $f(x)$ is increasing so $f(x)$ is one-one function.
(B)$f(x)=\operatorname{sgn}\left(\frac{1-|x|}{1+|x|}\right) $
$D_f=R $
$R_f=\{-1,0,1\} \text { even function }$
image
(C) For domain of $f(x)$, we must have $8-2 x-x^2 \geq 0$
$\Rightarrow x^2+2 x-8 \leq 0 $
$\Rightarrow(x+4)(x-2) \leq 0 $
$\Rightarrow x \in[-4,2]$
$R _{ f }=[0,3]$
image
(D)$\left.f(x)=\frac{2^{-[x]}}{2^{\{x\}}}-2^{|x|}=2^{-x}-2^{|x|}=0 \forall x \leq 0\right]$