00:01
All right, we're going to show, given our intuitive knowledge of the derivative, that all linear functions with positive slope are increasing everywhere.
00:12
So suppose you have a linear function, f of x equals mx plus b, doesn't matter what b is.
00:20
M is greater than zero.
00:22
All right.
00:23
So the average rate of change of f on the interval ab is what? it's going to be f of b minus f of a over b minus a, right? well, f of, oh, excuse me, this should probably be something like y zero, right? or the y intercept? sure.
00:56
This is going to be m times b plus y0 minus m times a minus y plus y 0 over b minus a, which is equal to let's see um b b plus y 0 minus m a plus or minus y 0 over b minus a minus a 0 over b minus a 0.
01:35
Y zeros will sum to zero and you will be left with m times b minus a over b minus a...