00:01
So for this problem, we ultimately are going to be talking about rates of change.
00:06
So this is getting into the idea of a derivative.
00:08
We have a change in distance.
00:10
So the d is referring to change.
00:16
And then the t is referring to time.
00:20
And the x is referring to distance.
00:23
And this is very similar to the idea of delta x over delta t.
00:27
But now this is a differential, so it's an instantaneous rate of change.
00:33
So we have a particle a moving at a constant rate of two units per second, and then particle b is going at three units per second.
00:46
When particle a is three units away from the origin, particle b is four units away from the origin, so we want to determine the rate of change of the distance between the two particles.
00:55
So the idea is, here's our x -axis and here's our y.
01:00
We have the origin.
01:04
Particle a is moving along the x -axis to, let's say, this point here.
01:13
And then particle b is moving along the y, let's say this point here.
01:21
And we see, we want to find the distance between them or the rate of change of the distance between them...
