Question
If $f(x) = {1 \over {1 - x}}$, then the derivative of the composite function $f[f\{ f(x)\} ]$ is equal to

Answer

c
(c) $f(x) = \frac{1}{{1 - x}}$ ==> $f\{ f(x)\} = \frac{{1 - x}}{{ - x}}$

$ \Rightarrow $ $f[f\{ f(x)\} ] = \frac{{ - x}}{{ - x - 1 + x}} = x$

$\therefore $ Derivative of $f[f\{ f(x)\} ] = 1$.

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

The value of the integral $\int_{0}^{\pi}|\sin 2 x| dx$ is
Let a line $L$ pass through the point $P (2,3,1)$ and be parallel to the line $x+3 y-2 z-2=0=x-y+2 z$. If the distance of $L$ from the point $(5,3,8)$ is $\alpha$, then $3 \alpha^2$ is equal to $......$.
If ${\cot ^{ - 1}}x + {\tan ^{ - 1}}3 = \frac{\pi }{2}$, then  $x =$
Let $\mathrm{n}$ be a non-negative integer. Then the number of divisors of the form " $4 \mathrm{n}+1$ " of the number $(10)^{10} \cdot(11)^{11} \cdot(13)^{13}$ is equal to $....$
The value of ${a^{{{\log }_b}x}}$, where $a = 0.2,\;b = \sqrt 5 ,\;x = \frac{1}{4} + \frac{1}{8} + \frac{1}{{16}} + .........$to $\infty $ is
The line $L$ passes through the points of intersection of the circles ${x^2} + {y^2} = 25$ and ${x^2} + {y^2} - 8x + 7 = 0$. The length of perpendicular from centre of second circle onto the line $L$, is
Let ${A_0}{A_1}{A_2}{A_3}{A_4}{A_5}$ be a regular hexagon inscribed in a circle of unit radius. Then the product of the lengths of the line segments ${A_0}{A_1},\,\,{A_0}{A_2}$ and ${A_0}{A_4}$ is
A function $f(x)$ is defined as $f(x) =\left[ {\begin{array}{*{20}{c}}  {{x^m}\,\sin \,\tfrac{1}{x}}&{x\,\, \ne \,\,0\,,\,\,\,m\,\, \in \,\,N} \\   0&{if\,\,\,\,\,x\,\, = \,\,0} \end{array}} \right. $ . The least value of $m$ for which $f ‘ (x)$ is continuous at $x = 0$ is
Let $A=\{2,3,6,7\}$ and $B=\{4,5,6,8\}$. Let $R$ be a relation defined on $A \times B$ by $\left(a_1, b_1\right) R\left(a_2, b_2\right)$ is and only if $a_1+a_2=b_1+b_2$. Then the number of elements in $R$ is __________ .
The area of the region bounded by $y=|| x-3|-4|-5$ and the $X$-axis is