List all the elements of the following sers :
$C = \{ x:x$ is an integer ${\rm{; }}{x^2} \le 4\} $
$C = \{ x:x{\rm{ }}$ is an integer ${\rm{ }};{x^2} \le 4\} $
It can be seen that
${( - 1)^2} = 1\, \le \,4;{( - 2)^2} = 4\, \le \,4;{( - 3)^2} = 9\, > \,4$
$0^{2}=0 \leq 4$
$1^{2}=1 \leq 4$
$2^{2}=4 \leq 4$
$3^{2}=9>4$
$\therefore C=\{-2,-1,0,1,2\}$
Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:
$ 0\, ........\, A $
If $Q = \left\{ {x:x = {1 \over y},\,{\rm{where \,\,}}y \in N} \right\}$, then
Write the set $\{ x:x$ is a positive integer and ${x^2} < 40\} $ in the roster form.
List all the elements of the following sers :
$D = \{ x:x$ is a letter in the word $"\mathrm{LOYAL}" $ $\} $
Examine whether the following statements are true or false :
$\{a\} \subset\{a, b, c\}$