MCQ
Choose the correct answer from the given four options. Let $f: R \rightarrow R$ be the functions defined by $f(x)=x^3+5$. Then $f^{-}$ ${ }^1(x)$ is:
  • A
    $(\text{x}+5)^\frac{1}{3}$
  • $(\text{x}-5)^\frac{1}{3}$
  • C
    $(5-\text{x})^\frac{1}{3}$
  • D
    $5-\text{x}$

Answer

Correct option: B.
$(\text{x}-5)^\frac{1}{3}$
we are given that, $\text{f}(\text{x})=\text{x}^3 +5$
Let us suppose, $\text{y}=\text{x}^3+5$
$\Rightarrow\ \text{x}^3=\text{y}-5$
$\Rightarrow\text{x}=(\text{y}-5)^{\frac{1}{3}}$
$\begin{bmatrix}\because\text{f}(\text{x})=\text{y}\\\Rightarrow\text{x}=\text{f}^{-1}(\text{y})\end{bmatrix}$
$\Rightarrow\text{f}^{-3}(\text{y})=(\text{y}-5)^{\frac{1}{3}}$
$\Rightarrow\text{f}^{-1}(\text{x})=(\text{x}-5)^{\frac{1}{3}}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A rectangle has one side on the positive $y-$ axis and one side on the positive $x -$ axis. The upper right hand vertex on the curve $y =\frac{{\ell nx}}{{{x^2}}}$ . The maximum area of the rectangle is
The value of the integral $\int_{\,\frac{1}{n}}^{\,\frac{{an - 1}}{n}} {\frac{{\sqrt x }}{{\sqrt {a - x} + \sqrt x }}dx} $ is
A random variable $X$ has the following distribution.
$X$12345678
$P(X)$0.150.230.120.100.200.080.070.05

For the event $E=\{X$ is prime number $\}$, find $P(E)$.
A fair die is tossed until six is obtained on it. Let $X$ be the number of required tosses, then the conditional probability $\mathrm{P}(\mathrm{X} \geq 5 \mid \mathrm{X}>2)$ is :
If $y = sin^{-1 }\left( {x\sqrt {1\,\, - \,\,x} \,\,\, + \,\,\,\sqrt x \,\,\sqrt {1\, - \,{x^2}} } \right) \&\,\, \frac{{dy}}{{dx}}= \frac{1}{{2\,\sqrt {x\,(1\,\, - \,\,x)} }}+ p$, then $p =$
Let $f (x) = \frac{{2{{\sin }^2}x - 1}}{{\cos x}} + \frac{{\cos x(2\sin x + 1)}}{{1 + \sin x}}$ then $\int e^x (f(x)+f'(x))dx$ (where $c$ is the constant of integeration)
If $h(a) = h(b),$ the value of the integral$\int_a^b {{{[f(g(h(x)))]}^{ - 1}}f'(g(h(x)))\,g'(h(x))\,h'(x)\,dx = } $
Let $p$ and $q$ be the position vectors of $P$ and $Q$ respectively with respect to $O$ and $|p|\, = p,\,\,|q|\,\, = q.$ The points $R$ and $S$ divide $PQ$ internally and externally in the ratio $2 : 3$ respectively. If $\overrightarrow {OR} $ and $\overrightarrow {OS} $ are perpendicular, then
If $D_1$ and $D_2$ are two $3 \times 3$ diagonal matrices, then
The sum of three numbers is $6 .$ If we multiply third number by $3$ and add second number to it, we get $11$. By adding first and third numbers, we get double of the second number. Represent it algebraically and find the numbers using matrix method.