Which of the following is the empty set
$\{ x:x$ is a real number and ${x^2} - 1 = 0\} $
$\{ x:x$ is a real number and ${x^2} + 1 = 0\} $
$\{ x:x$ is a real number and ${x^2} - 9 = 0\} $
$\{ x:x$ is a real number and ${x^2} = x + 2\} $
In the following state whether $\mathrm{A = B}$ or not :
$A = \{ x:x$ is a multiple of $10\} ;B = \{ 10,15,20,25,30 \ldots \ldots \} $
Write the following intervals in set-builder form :
$\left[ {6,12} \right]$
The number of non-empty subsets of the set $\{1, 2, 3, 4\}$ is
Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:
$ 8\, .......\, A $
Which of the following are sets ? Justify your answer.
The collection of questions in this chapter.