First, you may want to visualize what is happening here.
Graph y=x^2. The graph is that of a parabola that opens up. Draw a horizontal line through y=2 and another through y=0 (which is really the x-axis). Put dots where the curve intersects these lines.
Draw vertical lines through the two dots where the curve intersects the horiz. line y=2. Note where these two lines intersect the x-axis. From your graph, you can approximate the domain: it is roughly [-1.414, 1.414], or [-sqrt(2), -sqrt(2).
You could also take the sqrt of all 3 terms in the given inequality.
Then sqrt(0) ≤ sqrt(x²) ≤ sqrt(2), which is equivalent to 0 ≤ |x| ≤sqrt(2).
This allows for negative x in [-sqrt(2), ).
The domain of this function is [-sqrt(2), +sqrt(2)].
The range is 0 ≤ y ≤ 2.
