00:01
I have d .y over dx equals e to the y squared all over y.
00:05
This is a differential equation because i have that dy over dx.
00:08
And if i want to get it back to a general solution, then i need to do the integral.
00:12
But first i would want to separate the variables.
00:15
So i would send the dx over to the right side because that gets it off the denominator.
00:20
But i noticed that really i have the wrong variable there with it.
00:25
So i'm going to need to move this entire rational over to the left side.
00:30
An easy way to do that is to use the reciprocal.
00:33
So if i use the reciprocal, that's me flipping that fraction so that this will cancel out.
00:40
So that reciprocal to keep things balanced goes over to the left side.
00:46
So my new line of work is going to be y over e to the y squared times dy equals just dx or i could write 1dx.
00:58
Now that my variables are separated, i'm ready to integrate.
01:04
Integrating on the left hand side, i want to do one important step first.
01:11
There's not like a great rule for having an e on the denominator.
01:16
So i actually can bring that e up to the numerator if i write the exponent as a negative, right? that will reciprocated for me.
01:26
So i'm going to write that exponent as a negative y squared to bring it up and everything else is going to stay the same.
01:30
And now it becomes more obvious to me that i can use a substitution here to make it just e to the u, which its anti -derivative stays the same.
01:40
It's still e to the u.
01:41
So we're going to replace this exponent, negative y squared, and i need to also check its derivative.
01:50
Well, the derivative would be negative 2y, d .y.
01:56
And i have some of that already here...