To celebrate the end of the semester, I humbly submit now a list of my differential equations professor's unintentionally hilarious quotes:
It’s falling because that’s what things do.
A differential equation is something with a lot of x’s.
If that’s a sense allowed in the English language.
Stand back! I’m about to do some basic arithmetic!
I don’t have your tests graded yet. They take time and… - (student) Excuses. – Oh, so you want to me grade them like I do finite – just get drunk and start marking them all 0 or 50? – (student) No. We’re good. Take your time.
Say you have p sheep and some of the sheep kill each other. These are vicious sheep.
Partial fractions! We should be having traumatic memories of Cal 2 right now.
All models are bad, but some are useful.
This dry-erase marker is larger than an atom.
We can employ the method of… whatever to solve that.
There’s a quote… the shortest path between two truths passes through the complex plane.
You know, I don’t like Roman numerals. Roman numerals are stupid. *rubs it out and puts a 1 instead*
Any questions on how to find T? I hope we only have to find it for T, not coffee. *takes a sip*
I think f needs to be continuous for this theorem. Eh, I don’t care.
Uh-oh. I’ve got c1and c2 switched in my notes. We’re in trouble.
I’m not an expert on differential equations. I’m just teaching this class because no one else wanted to.
Is everyone kind of okay with this?
Okay, just pretend I’m allowed to multiply. Turns out I am. There’s probably a theorem somewhere to prove it.
We will solve this for the general solution, which is the answer of… whatever form for all questions like this.
(on SIR epidemic model) A recovered individual may or may not be dead. This model includes the dead people in the recovered. They are no longer infectious and are immune to further infection. I guess they’re not zombies, since they’re no longer infectious.
(on Laplace translation theorem) This theorem will not tell you how to calculate the Laplace transform in Spanish. De transformada de Laplace. No, we mean geometric translation.
This is an important theorem, which we won’t prove. Hooray.
It’s a fact from… somewhere… that an irreducible quadratic can be written as a sum of two squares. You probably remember from algebra, how you could write it with arctan… Well, we’re doing something else now.
It will be the solution, the only solution, by some uniqueness theorem.
Okay, over here I have DE world, and over here I have Laplace world. This is the left side of the chart, and this is the right.
First I have to kill that 2 in front of x’.
This is one of our favorite methods from Cal 2. And how many times do we need to use it? Dos!
Is everyone okay with how we found x? The battle for x is over.
I think there is an arbitrary constant somewhere that I missed that’s important. Sorry, guys.
How about #4? Wait, I think we did #4 in class. How about #6? No, it looks like #4. Let’s do #8.
Why did we solve for F(x,y)? – (student) Because you told us to.
