00:01
All right, so let's say we're dealing with a circle, and we have an uncertainty in our measurement of r.
00:05
So r has an uncertainty associated with a delta r.
00:10
So the uncertainty in a, given that r enters in with an exponent of 2, divided by a, is going to equal like 2.
00:20
Or better yet, let's put it this way.
00:22
Uncertainty in a was going to be like 2 pi r times our uncertainty in r.
00:28
And we can write 2 pi r as our area times our times 2, or sorry, our area divided by r times 2.
00:40
So we've got something like this.
00:42
And so that means delta a over a is equal to 2 delta r over r...