MCQ
The function $g (x) =$ $\left[ \begin{gathered}   \hfill \\   \hfill \\ \end{gathered}  \right.$$\begin{gathered}  x + b,\,\,\,x < 0 \hfill \\   \hfill \\  \cos x,\,\,\,x \geqslant 0 \hfill \\ \end{gathered} $ can be made differentiable at $x = 0.$
  • A
    if $b$ is equal to zero
  • B
    if $b$ is not equal to zero
  • C
    if $b$ takes any real value
  • for no value of $b$

Answer

Correct option: D.
for no value of $b$
d
$g’ (0^+) =$$\mathop {Lim}\limits_{h \to 0} \,\frac{{\cosh  - 1}}{h}$ $= 0$
$g ‘ (0^-) =$$\mathop {Lim}\limits_{h \to 0} \,\frac{{ - h + b - 1}}{{ - h}}$ for existence of line $b = 1$ thus $g ‘ (0^-) = 1$
Hence $g$ can not be made differentiable for any value of $b$.

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

Let $f : R \rightarrow R$ be defined as  $f(x)\, = \,{3^{ - \left| x \right|}} - {3^x} + \operatorname{sgn} ({e^{ - x}}) + 2$

(whre $\operatorname{sgn} x$ denotes signum function of $x$). Then
which one of the following is correct ?

$\int \frac{\left(x^{2}+1\right) e^{x}}{(x+1)^{2}} d x=f(x) e^{x}+C$, Where $C$ is a constant, then $\frac{d^{3} f}{d x^{3}}$ at $x =1$ is equal to
If a function $f(x)$ is such that $f\left( {x + \frac{1}{x}} \right) = {x^2} + \frac{1}{{{x^2}}};$ then  $(fof )$ $\sqrt {11} )$ =
The area bounded by $y –1 = |x|, y = 0$ and $|x| \frac{1}{2}$ will be:
The value of  $\tan \left( {\frac{1}{2}{{\cos }^{ - 1}}\left( {\frac{{\sqrt 5 }}{3}} \right)} \right)$ is
Let $f(x) = [2x^3 -5];$ then number of points in $(1, 2)$ where the function is discontinuous are where $[\,.]\, \to G.I.F$
If $a, b, c $ are three non-coplanar vectors such that $a + b + c = \alpha \,d$ and $b + c + d = \beta \,a,$ then $a + b + c + d$ is equal to
If the lines $\text{x}- \frac{2}{1} =\text{y}-\frac{2}{1} =\text{z}-\frac{4}{\text{k}} $ and $\text{x}-\frac{1}{\text{k}} = \text{y}-\frac{4}{2} = \text{z}-\frac{5}{1} $ are coplanar, then $k$ can have:
4 numbers are taken from 1, 2, 3, 4, 5, 6, 7. Probability of getting sum of 4 numbers is less than 12 .
Which of the following is(are) $NOT$ the square of a $3 \times 3$ matrix with real entries ?

$[A]$ $\left[\begin{array}{ccc}1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & -1\end{array}\right]$

$[B]$ $\left[\begin{array}{ccc}-1 & 0 & 0 \\ 0 & -1 & 0 \\ 0 & 0 & -1\end{array}\right]$

$[C]$ $\left[\begin{array}{lll}1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1\end{array}\right]$

$[D]$ $\left[\begin{array}{ccc}1 & 0 & 0 \\ 0 & -1 & 0 \\ 0 & 0 & -1\end{array}\right]$