MCQ Bank
$${\text{If }}{\mathbb{R}^n}{\text{ is connected, such that }}{\mathbb{R}^n} = A \cup B{\text{ with }}\bar A \cap B = A \cap \bar B = \phi ,{\text{then - - - - - }}{\text{.}}$$
- A) $${\text{All above can be concluded}}$$
- B) $${\text{Either }}A = {\mathbb{R}^n},B = \phi {\text{ or }}B = {\mathbb{R}^n},A = \phi$$
- C) $$A{\text{ and }}B{\text{ are both open and closed}}$$
- D) $${\text{ }}\bar A \subset A,\bar B \subset B$$
A set “ S ” is polygonally connected if, ------- pair of points in S can be connected by a polygonal path lying -------- in “ S ”.
- A) every, partially
- B) some, entirely
- C) every , entirely
- D) some, partially
${\text{If }}\phi \ne S \subseteq {\mathbb{R}^n},{\text{ then the set }}S{\text{ is bounded if - - - - - - - }}{\text{.}}$
- A) ${\text{sup}}\left\{ {\left| {X - Y} \right|:X,Y \in S} \right\} < \infty \,$
- B) $\inf \left\{ {\left| {X - Y} \right|:X,Y \in S} \right\} < \infty$
- C) $\inf \left\{ {\left| {X - Y} \right|:X,Y \in S} \right\} = \infty$
- D) ${\text{sup}}\left\{ {\left| {X - Y} \right|:X,Y \in S} \right\} = \infty$
$\begin{gathered} {\text{In }}{\mathbb{R}^3},{\text{ the lines }}{{\text{L}}_{\text{1}}}:X = \left( {2, - 1,5} \right) + \alpha \left( {2, - 1,3} \right){\text{ and }}{{\text{L}}_2}:X = \left( {2, - 1,5} \right) + \beta \left( { - 5,\frac{5}{2}, - \frac{{15}}{2}} \right){\text{ are traversed}} \hfill \\ {\text{in - - - - - - - - - directions, where }} - \infty < \alpha ,\beta < \infty . \hfill \\\ \end{gathered}$
- A) ${\text{opposite}}$
- B) ${\text{perpendicular}}$
- C) ${\text{oblique}}$
- D) ${\text{same}}$
$${\text{Which of the following non - empty subset on Real line }}\mathbb{R}{\text{ is taken as }}region\,?$$
- A) $${\text{Range of pointwise or uniform real valued convergent sequences}}$$
- B) $${\text{Natural numbers }}\mathbb{N}$$
- C) $${\text{Rationals }}\mathbb{Q}{\text{ or Irrationals }}{\mathbb{Q}^c}$$
- D) $${\text{Intervals (open, closed, semi open or closed)}}$$
${\text{In }}{\mathbb{R}^n},\,{\text{the interior }}{S^0}{\text{ of a non - empty set S is - - - - - - }}{\text{.}}$
- A) ${\text{open - connected (region)}}$
- B) ${\text{open - disconnected}}$
- C)
- D)
$${\text{Which of the following non - empty subset on Real line }}\mathbb{R}{\text{ is taken as }}region\,?$$
- A) $${\text{Rationals }}\mathbb{Q}{\text{ or Irrationals }}{\mathbb{Q}^c}$$
- B) $${\text{Range of pointwise or uniform real valued convergent sequences}}$$
- C) $${\text{Natural numbers }}\mathbb{N}$$
- D) $${\text{Intervals (open, closed, semi open or closed)}}$$
$${\text{Set of isolated point(s) of the complement of set }}\left\{ {\left( {x,y} \right): - n < x,y < n,\left( {x,y} \right) \ne \left( {0,0} \right),n \in \mathbb{N}} \right\}{\text{ in }}{\mathbb{R}^{\text{2}}},{\text{is}} - - - - .$$
- A) $$\left\{ {\left( {x,y} \right) \in {\mathbb{R}^2}:x = y = \left| n \right|,n \in \mathbb{N}} \right\} \cup \left\{ {\left( {0,0} \right)} \right\}$$
- B) $$\left\{ {\left( {x,y} \right) \in {\mathbb{R}^2}:x = y = \left| n \right|,n \in \mathbb{N}} \right\}$$
- C) $$\left\{ {\left( {x,y} \right) \in {\mathbb{R}^2}:x = y = \left| n \right|,n \in \mathbb{N}} \right\} \cap \left\{ {\left( {0,0} \right)} \right\}$$
- D) $$\left\{ {\left( {0,0} \right)} \right\}$$
\[{\text{In }}{\mathbb{R}^2},{\text{ the set }}\left\{ {\left( {x,y} \right):\left( {{x^2} + {y^2} \leqslant a} \right)\,\, \vee \,\left( {{x^2} + {y^2} \geqslant b} \right),a < b} \right\}\,{\text{is a region}}{\text{.}}\]
- A) False
- B) True
- C)
- D)
The limit of the function $f(x) = \frac{{xy}}{{{x^2} + {y^2}}}$ by letting $\left( {x,{\rm{ }}y} \right)$approach $\left( {0,{\rm{ }}0} \right)$along the line $y{\rm{ }} = {\rm{ }}x$ is ________.
- A) $$- \frac{1}{2}$$
- B) $$\frac{1}{2}$$
- C) Finite
- D) Undefined
${\text{If }}\phi \ne S \subseteq {\mathbb{R}^n},{\text{ then the set }}S{\text{ is bounded if - - - - - - - }}{\text{.}}$
- A) ${\text{sup}}\left\{ {\left| {X - Y} \right|:X,Y \in S} \right\} = \infty $
- B) ${\text{sup}}\left\{ {\left| {X - Y} \right|:X,Y \in S} \right\} < \infty \,$
- C) $\inf \left\{ {\left| {X - Y} \right|:X,Y \in S} \right\} = \infty $
- D) $\inf \left\{ {\left| {X - Y} \right|:X,Y \in S} \right\} < \infty $
${\text{A compact set in }}{\mathbb{R}^n}{\text{ is - - - - - - - - - - }}{\text{.}}$
- A) ${\text{closed and bounded}}$
- B) ${\text{closed and unbounded}}$
- C) ${\text{open and unbounded}}$
- D) ${\text{open and bounded}}$
${\text{An open disc: }}\left\{ {\left( {x,y} \right):{x^2} + {y^2} < 1} \right\}{\text{ in }}{\mathbb{R}^2}{\text{ is - - - - - - }}{\text{.}}$
- A) ${\text{connected polygonally}}$
- B) ${\text{diconnected}}$
- C) ${\text{disconnected polygonally}}$
- D) ${\text{none of these}}{\text{.}}$
$$\begin{gathered} {\text{In }}{\mathbb{R}^n}{\text{, if }}{S_1},{S_2},{S_3} \ldots \,\,{\text{are non - empty closed subsets such that }}{S_1} \supset {S_2} \supset \cdots \; \supset {S_r} \supset \cdots {\text{ and }} \hfill \\ {\text{sup}}\left\{ {\left| {{X_r} - {Y_r}} \right|:{X_r},{Y_r} \in {S_r},r \geqslant 1} \right\} \to 0{\text{ as }}r \to \infty {\text{,then the order of set }}\mathop \cap \limits_{r = 1}^\infty {S_r} = - - - . \hfill \\\ \end{gathered}$$
- A) $$\operatorname{infinite}$$
- B) $${\text{one}}$$
- C) $${\text{finite but more than one}}$$
- D) $${\text{zero}}$$
$\begin{gathered} {\text{In }}{\mathbb{R}^3},{\text{ the lines }}{{\text{L}}_{\text{1}}}:X = \left( {2, - 1,5} \right) + \alpha \left( {2, - 1,3} \right){\text{ and }}{{\text{L}}_2}:X = \left( {2, - 1,5} \right) + \beta \left( { - 5,\frac{5}{2}, - \frac{{15}}{2}} \right){\text{ are traversed}} \hfill \\ {\text{in - - - - - - - - - directions, where }} - \infty < \alpha ,\beta < \infty . \hfill \\\ \end{gathered}$
- A) ${\text{perpendicular}}$
- B) ${\text{same}}$
- C) ${\text{opposite}}$
- D) ${\text{oblique}}$
${\text{The set }}\left\{ {\left( {x,y} \right): - n < x,y < n,\left( {x,y} \right) \ne \left( {0,0} \right),n \in \mathbb{N}} \right\}{\text{ is - - - - - - in }}{\mathbb{R}^{\text{2}}}.$
- A) open
- B) neither open nor closed
- C) closed
- D) both open or closed
A set A ⊂ R of real numbers is ------------------if there exists a real number m ∈ R, such that
x ≥ m for every x ∈ A.
- A) None of these
- B) bounded above
- C) uniformly continuous
- D) bounded below
$$\begin{gathered} {\text{If a function }}f{\text{ is }}continuous{\text{ on a }}compact{\text{ set }}S{\text{ in }}{\mathbb{R}^n}{\text{, and }}\alpha = \mathop {\inf }\limits_{X \in S} f\left( X \right),\,\beta = \mathop {\sup }\limits_{X \in S} f\left( X \right)\,, \hfill \\ {\text{then }}f\left( {{X_1}} \right){\text{ = }}\alpha {\text{ and }}f\left( {{X_2}} \right){\text{ = }}\beta \, - - - - - {X_1}{\text{ and }}{X_2}{\text{ in }}S. \hfill \\\ \end{gathered}$$
- A) for all
- B) for some
- C)
- D)
$${\text{If }}f\left( t \right) = \sqrt t {\text{, }}g\left( {x,y} \right) = 1 - {x^2} - 2{y^2}{\text{, then the domain of }}f \circ g = {\text{ - - - - - - }}{\text{.}}$$
- A) $$\mathbb{R}$$
- B) $$\left\{ {\left( {x,y} \right):{x^2} - 2{y^2} \leqslant 1} \right\}$$
- C) $${\mathbb{R}^2}$$
- D) $$\left\{ {\left( {x,y} \right):{x^2} - 2{y^2} \geqslant 1} \right\}$$
Identify the true statement(s)
- A) For a functions of $n$ variables $$f({\mathbf{X}})$$ the partial derivative with respect to variable $${x_2}$$ is $$\frac{{\partial f({\mathbf{X}})}}{{\partial {{\mathbf{E}}_2}}}$$
- B) A function of several variables is continuous then it is differentiable.
- C) A function of several variables is differentiable if all of its partial derivatives exists.
- D) $$L(x) = 2x - 3{x^2}$$ is a linear function.