00:01
Okay, so i have our differential equation written up in the top as well as our point that we need to have one of our approximate solutions go through.
00:10
So what i'm going to do is using this graph field below, i'm just going to sketch two curves that are approximate solutions to our differential equation.
00:19
And so for the first one, i'm going to start at zero zero.
00:23
And how i'm going to sketch this is just by looking at how these lines change as i'm going in the positive x direction.
00:30
And then draw a curve that does something similar.
00:35
And if we look at these lines, it seems like they're gradually getting more positive.
00:41
So we want a gradually increasing curve to look something like that.
00:48
And then as we go in the negative x direction, we can see that these are getting gradually more negative.
00:56
Their slopes are.
00:57
And so what we want is a curve that does something similar.
01:08
So something like that.
01:10
And if we looked a little closer, we'd see that these curves or these slopes at the points are actually the opposite of each other.
01:18
If we were to look at point the slope at 0 .2 or 0 .2, it would be the opposite of the slope at 0 .2.
01:29
And so now after we have this first curve, i'm going to draw a second one that goes through our point 0 .0 .5, which is right here.
01:39
And so since our differential equation, our dsd t, it doesn't actually depend on our s value or on our y value.
01:49
You can think of the y axis as the s axis and the x axis as the t axis...