Range tells you how high and low the graph of this parabola goes in the “y” (vertical) directions.
1. We can see that the parabola peaks on the y-axis at y = 4. That’s as HIGH as it goes.
2. We also see that both sides of the parabola descend to the level of y = -7. That’s as LOW as it is shown to go.
So putting these together, we say the Range is given by:
-7 <= y <= 3
AMBIGUITY WARNING:
Because the two branches of the parabola go fall right down to the edge of the picture boundary, it’s UNCLEAR whether the parabola truly stops at y = -7 or CONTINUES on (to negative infinity).
In THAT case, the RANGE simplifies to:
Y <= 4
Done.