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
${( - 1)^2} = 1\, \le \,4;{( - 2)^2} = 4\, \le \,4;{( - 3)^2} = 9\, > \,4$
$0^{2}=0 \leq 4$
$1^{2}=1 \leq 4$
$2^{2}=4 \leq 4$
$3^{2}=9>4$
$\therefore C=\{-2,-1,0,1,2\}$
Write the solution set of the equation ${x^2} + x - 2 = 0$ in roster form.
Examine whether the following statements are true or false :
$\{ a,b\} \not\subset \{ b,c,a\} $
Make correct statements by filling in the symbols $\subset$ or $ \not\subset $ in the blank spaces:
$\{ x:x$ is an equilateral triangle in a plane $\} \ldots \{ x:x$ is a triangle in the same plane $\} $
Make correct statements by filling in the symbols $\subset$ or $ \not\subset $ in the blank spaces:
$\{ x:x$ is a student of class $\mathrm{XI}$ of your school $\} \ldots \{ x:x$ student of your school $\} $
$A = \{ x:x \ne x\} $ represents