I need help determining the rang of this graph

The highest point is when y = 0 and the lowest point is when y = -5

We can see this if we draw horizontal lines through the highest and lowest points (see the diagram below). Note where the horizontal lines cross the y axis. For y = 0, we don't really need a horizontal line but I'll draw it anyway.

Since y ranges from y = -5 to y =0, the range is therefore

Side note: to write this in interval notation, you would say . The square brackets say to include each endpoint as part of the range.

it is 10.6 according to my calculations