Question
The function $\text{f{x}}\begin{cases}1,&|\text{x}|\geq1\\\frac{1}{\text{n}^2},&\frac{1}{\text{n}}<|\text{x}|<\frac{1}{\text{n}-1},\text{n}=2,3,...\end{cases}$
  1. Is discontinuous at finitely many points.
  2. Is continuous everywher.
  3. Is discontinuous only at $\text{x}=\pm\frac{1}{\text{n}},\text{n }\in\text{ z}-\{0\}$ and x = 0
  4. None of these.

Answer

  1. Is discontinuous only at $\text{x}=\pm\frac{1}{\text{n}},\text{n }\in\text{ z}-\{0\}$ and x = 0

Solution:

Given function is

$\text{f{x}}\begin{cases}1,&|\text{x}|\geq1\\\frac{1}{\text{n}^2},&\frac{1}{\text{n}}<|\text{x}|<\frac{1}{\text{n}-1},\text{n}=2,3,...\end{cases}$

Consider,

$\lim\limits_{\text{x}\rightarrow\frac{1}{\text{n}}^-}\text{f(x)}=\frac{1}{\text{n}^2}$

$\lim\limits_{\text{x}\rightarrow\frac{1}{\text{n}}^+}\text{f(x)}=\lim\limits_{\text{x}\rightarrow\frac{1}{\text{n}}}1=1$

Hence, fnuction is discontinuous at $\text{x}=\pm\frac{1}{\text{n}},\text{n }\in\text{ z}-\{0\}$ and x = 0

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 R be the relation on the set A = {1, 2, 3, 4} given by R = {(1, 2), (2, 2), (1, 1), (4, 4), (1, 3), (3, 3), (3, 2)}. Then,
  1. R is reflexive and symmetric but not transitive.
  2. R is reflexive and transitive but not symmetric.
  3. R is symmetric and transitive but not reflexive.
  4. R is an equivalence relation.
If $\text{P(A)}=\frac{2}{5},\text{P(B)}=\frac{3}{10}$ and $\text{P}(\text{A}\cap\text{B})=\frac{1}{5},$ then, $\text{P}(\overline{\text{A}}|\overline{\text{B}}) \text{ P}(\overline{\text{B}}|\overline{\text{A}})$ is equal to
  1. $\frac{5}{6}$
  2. $\frac{5}{7}$
  3. $\frac{25}{42}$
  4. $1$
The values of $x,y,z$ in order of the system of equations $3x + y + 2z = 3,$ $2x - 3y - z = - 3$, $x + 2y + z = 4,$ are
If $\text{A}=\frac{1}{3}\begin{bmatrix} 1 & 1 & 2 \\ 2 & 1 & -2 \\ \text{x} & 2 & \text{y} \end{bmatrix}$ is prthogonal, than x + y =
  1. 3
  2. 0
  3. -3
  4. 1
Which of the following is not a decreasing function on the interval $\left( {0,{\pi \over 2}} \right)$
If $|a|\,\, = 3,\,\,\,|b|\,\, = 1,\,\,|c|\,\, = 4$ and $a + b + c = 0,$ then $a\,.\,b + b\,.\,c + c\,.\,a = $
The general solution of the differential equation, $x \left( {\frac{{dy}}{{dx}}} \right) = y \cdot \ln \left( {\frac{y}{x}} \right)$ is :
where $c$ is an arbitrary constant.
If $\text{f(x)}=\begin{cases}\frac{1}{1+\text{e}^{\frac{1}{\text{x}}}},&\text{x}\neq0\\0,&\text{x}=0\end{cases}$ then f(x) is:
  1. Continuous as well as differentiable at x = 0
  2. Continuous but not differentiable at x = 0
  3. Differentiable but not continuous at x = 0
  4. None of these.
The shortest distance between the lines $\frac{x-3}{2}=\frac{y-2}{3}=\frac{z-1}{-1}$ and $\frac{x+3}{2}=\frac{y-6}{1}=\frac{z-5}{3}$ is
The angle between the lines whose direction cosines satisfy the equations $l + m + n = 0$, ${l^2} + {m^2} - {n^2} = 0$ is given by