00:01
Given the function f of x equals x squared minus 2, on the interval negative 4 to 8, we are supposed to find the average rate of change.
00:10
Well, the average rate of change is another way of saying the slope over that interval negative 4 to 8.
00:19
Part of your question requires sketching a graph of the function.
00:22
I've already made my sketch here, and i'm going to just go over how i would do that, because some of the values that i have here are necessary for finding the average rate of change.
00:34
Okay, so first of all, we're on the interval negative 4 to 8.
00:40
So that means i would want to know what f of negative 4 is, which is just negative 4 squared minus 2, or 16 minus 2, which is 14.
00:55
I'd also want to know what f of 8 is, and that would be 8 squared minus 2, or 64 minus 2, or 62.
01:06
So now you can actually see how i found this point and this point, because the coordinates would be negative 4 and 14, and 8, and 62.
01:21
Also, you should know that basically you're graphing a parabola, and it has been moved down to, so that's how i knew to locate the vertex...