In my textbook , it says x ∈ (-$\infty$ , 0) U (0,2).
Then , squaring the two brackets.
($\infty$,0$ and ( 0 ,4 )
Arranging it ( 0 ,4 ) U ($\infty$,0$).
Therefore , x belongs to 0,$\infty$.
Now , my questions are:
1) According to the Q , $x^2$ are we only wish to find , we need want them to satisfy like $x^2$ < 4. Squaring the possible values , we should get ($4$ , $\infty$) as the possible values if i in the starting only took (-$\infty$,2). Why do we see loss of values from 0 to 4 in this case ?