MCQ
For any set $A, (A')'$ is equal to:
  • A
    $A'$
  • $A$
  • C
    $\phi$
  • D
    None of these.

Answer

Correct option: B.
$A$
The complement of the complement of a set is the set itself.

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

Tangent and normal are drawn at $P(16, 16)$ on the parabola ${y^2} = 16x$, which intersect the axis of the parabola at $A$ and $B$, respectively. If $C$ is the centre of the circle through the points  $P, A$ and $B$ and $\angle CPB = \theta $ , then a value of $\tan \theta \;$is :
The equation of the straight line passing through the point $(3, 2)$ and perpendicular to the line $y = x$ is
If the variance of the frequency distribution is $160$ , then the value of $\mathrm{c} \in \mathrm{N}$ is
$X$ $c$ $2c$ $3c$ $4c$ $5c$ $6c$
$f$ $2$ $1$ $1$ $1$ $1$ $1$
If $\text{f}(\text{x})=\begin{cases}\text{x}^{2}-1 & 0<\text{x}<2\\2\text{x}+3, & 2\geq\text{3}<3\end{cases}$ then the quadeatic equation whose roots are $\lim\limits_{\text{x} \rightarrow 2^{-}}\text{f}(\text{x})$ and $\lim\limits_{\text{x} \rightarrow 2^{+}}\text{f}(\text{x})$ is:
Let $f(x) = x - [x] \in R,$ then $\text{f}\Big(\frac{1}{2}\Big)$ is:
The domain of the function $y = \frac{1}{{\sqrt {|x|\; - x} }}$ is
The difference of the focal distances of any point on the hyperbola is equal to
The cube roots of unity when represented on the Argand plane form the vertices of an       [IIT 1988; Pb. CET 2004]
Let $S$ be the set of all complex numbers $z$ satisfying $\left|z^2+z+1\right|=1$. Then which of the following statements is/are $TRUE$?

$(A)$ $\left|z+\frac{1}{2}\right| \leq \frac{1}{2}$ for all $z \in S$  $(B)$ $|z| \leq 2$ for all $z \in S$

$(C)$ $\left|z+\frac{1}{2}\right| \geq \frac{1}{2}$ for all $z \in S$  $(D)$ The set $S$ has exactly four elements

Let $X=\{x \in R: \cos (\sin x)=\sin (\cos x)\} .$ The number of elements in $X$ is