With graphs like this, when you have the lowest point, you follow these steps:
Step 1) Find the lowest point. The lowest point is (1,-4)
Step 2) Find the y coordinate of this lowest point. The y coordinate is y = -4
The range is the set of possible y output values of a function. The range in this case is the set of real numbers y such that
(y is greater than or equal to -4). Basically y can equal -4 or it can be larger than -4. It is not possible for y to be smaller than -4