MCQ
The function $f(x) = ({x^2} - 1)|{x^2} - 3x + 2| + \cos (|x|)$ is not differentiable at
  • A
    $-1$
  • B
    $0$
  • C
    $1$
  • $2$

Answer

Correct option: D.
$2$
d
(d) Since function $|x|$ is not differentiable at $x = 0$

$\therefore \,|{x^2} - 3x + 2| = |(x - 1)(x - 2)|$

Hence is not differentiable at $x = 1$ and $2$

Now $f(x) = ({x^2} - 1)|{x^2} - 3x + 2|\cos (|x|)$ is not differentiable at $x = 2$

For $1 < x < 2$, $f(x) = - ({x^2} - 1)({x^2} - 3x + 2) + \cos x$

For $2 < x < 3$, $f(x) = + ({x^2} - 1)({x^2} - 3x + 2) + \cos x$

$Lf'(x) = - ({x^2} - 1)(2x - 3) - 2x({x^2} - 3x + 2) - \sin x$

$Lf'(2) = - 3 - \sin 2$

$Rf'(x) = ({x^2} - 1)(2x - 3) + 2x({x^2} - 3x + 2) - \sin x$

$Rf'(2) = (4 - 1)(4 - 3) + 0 - \sin 2 = 3 - \sin 2$

Hence $Lf'(2) \ne Rf'(2)$.

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 real function $f(x)=2 x^3-3 x^2-36 x+7$ is
The following system of equation $3x - 2y + z = 0$, $\lambda x - 14y + 15z = 0$, $x + 2y - 3z = 0$ has a solution other than $x = y = z = 0$ for $\lambda $ equal to
Let $f :R \to R$ be a function defined as $f\left( x \right) = \left\{ \begin{array}{l}
5,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,if\,\,\,\,\,\,\,x \le 1\,\,\,\,\,\,\,\\
a + bx,\,\,\,\,if\,\,\,\,\,\,1 < x < 3\\
b + 5x,\,\,\,\,if\,\,\,\,\,\,3 \le x < 5\\
30,\,\,\,\,\,\,\,\,\,\,if\,\,\,\,\,\,\,x \ge 5
\end{array} \right.\,\,\,\,$ Then $f$ is
An urn contains 9 balls two of which are red, three blue and four black. Three balls are drawn at random. The probability that they are of the same colour is,
  1. $\frac{5}{84}$
  2. $\frac{3}{9}$
  3. $\frac{3}{7}$
  4. $\frac{7}{17}$
Given that for each $a \in(0,1)$

$\lim _{n \rightarrow 0^{+}} \int_n^{1-n} t^{-3}(1-t)^{a-1} d t$

exists. Let this limit be $g(a)$. In addition, it is given that the function $g(a)$ is differentiable on $(0,1)$.

$1.$ The value of $g\left(\frac{1}{2}\right)$ is

$(A)$ $\pi$ $(B)$ $2 \pi$ $(C)$ $\frac{\pi}{2}$ $(D)$ $\frac{\pi}{4}$

$2.$ The value of $g ^{\prime}\left(\frac{1}{2}\right)$ is

$(A)$ $\frac{\pi}{2}$ $(B)$ $\pi$ $(C)$ $-\frac{\pi}{2}$ $(D)$ $0$

Give the answer question $1$ and $2.$

$\left[ \begin{array}{l}\,\,\,1\\ - 1\\\,\,\,2\end{array} \right]\,\,[2{\rm{ }}\,\,1{\rm{ }} - 1]$ =
The problem associated with LPP is:
Let $f(x)$ be a polynomial of degree $3$ such that $f(-1)=10, f(1)=-6, f(\mathrm{x})$ has a critical point at $\mathrm{x}=-1$ and $f^{\prime}(\mathrm{x})$ has a critical point at $\mathrm{x}=1$ Then $f(x)$ has a local minima at $x=$
A ship is fitted with three engines $E_1, E_2$ and $E_3$. The engines function independently of each other with respective probabilities $\frac{1}{2}, \frac{1}{4}$ and $\frac{1}{4}$. For the ship to be operational at least two of its engines must function. Let $X$ denote the event that the ship is operational and let $X _1, X _2$ and $X _3$ denotes respectively the events that the engines $E_1 E_2$ and $E_3$ are functioning. Which of the following is (are) true?

$(A)$ $P\left[X_1^c \mid x\right]=\frac{3}{16}$

$(B)$ $P [$ Exactly two engines of the ship are functioning $\mid X ]=\frac{7}{8}$

$(C)$ $P\left[X \mid X_2\right]=\frac{5}{16}$

$(D)$ $P\left[X \mid X_1\right]=\frac{7}{16}$

Choose the correct answer from the given four options.
Let f : [2, ∞) → R be the function defined by f(x) = x2 – 4x + 5, then the range of f is:
  1. $\text{R}$
  2. $[1,\infty)$
  3. $[4,\infty)$
  4. $[5,\infty)$