00:01
Okay, so there's a few different definitions of the derivative, but you can just use the one that you prefer.
00:06
They are all the same, and this is the one that i prefer to use.
00:10
So my definition is that the derivative of f with respect to x is the limit as h tends to zero of f of x plus h minus f of x, all divided by h.
00:29
And i'm going to talk to you about the geometric interpretation now.
00:34
So what we're going to do is choose a point on this graph, and you don't have to have a graph like this, you can choose any graph you prefer.
00:42
So i'm going to say choose this point here, and i'm also going to choose, let's go for this one up here.
00:50
That one looks pretty nice.
00:52
Okay, so this is my point x.
00:55
Now of course you can see that it has an actual value, you can calculate that that's 1 .5, but we're not worried about that.
01:01
And this is my point that's just a little bit bigger than x, i'm going to call it x plus h.
01:08
So that's what the x coordinate is...