The best thing to do here is to graph y=x^2-3
If you don't have a graphing calculator you can do this by plugging in values for x and solving for y
Let's start with x=0
plug in 0 for x
y=0^2-3
y=-3
So our first point on our graph would be x=0, y=-3 or (0,-3)
then we can do the same thing for x=1
plug in 1 for x
y=1^2-3
y=-2
So our next point is x=1, y=-2 or (1,-2)
then the same for x=-1
plug in -1 for x
y=-1^2-3
y=-2
So our next point is x=-1, y=-2 or (-1,-2)
If you put those points on your graph and connect them you will see that this makes a parabola which has a vertex that is located on the y axis at (0,-3) and opens up.
Now since this is y<x^2-3 we need to shade anything below the parabola. The final graph will look something like this: