Skip to content ↓
MIT student blogger Keri G. '10

If the roots are imaginary, then the dots will be blue… by Keri G. '10

Diff EQ what now?

As it’s been nearly a month since I posted (yeah. I’ve been hosed. I still am – I just got out of my 8.02 final, and I have 5.12 tomorrow.), I decided that upon my return, I’d treat you to my collection of 18.03 quotes, all said by longtime professor Arthur Mattuck. (He’s been teaching here for over 40 years!) These quotes have peppered my notebook all term, so I’ve compiled the best of them here. Enjoy!

“If the roots are imaginary, then the dots in the applet will be blue.” (Draws dots in orange on board, waves chalk in the air.) “See? Blue.”

“And now I’m reminded of an old joke, which I will not tell you.”

“If I give you a colossal drug dosage then you’ll be dead, and the differential equation we just spent the entire class on won’t apply anymore.”

“You can tell this is an integral because I’m acting like it’s going to be an integral.”

“I think I’d better have some colored chalk in my hand; otherwise, everything will be in white and nothing will be intelligible.”

“Let’s see if we can factor this. This being 18.03 and not real life, we can always factor it.”

And my favorites, these two extended examples:

“Say there’s an arms race between New Hampshire and Vermont, them being right next to each other and all. New Hampshire suspects Vermont of sneaking across the border and attempting to destroy the Old Man on the Mountain, effectively ruining the state’s tourist trade. Meanwhile, Vermont suspects New Hampshire of smuggling Canadian maple syrup. The differential equations representing the change in the number of arms each country has are dependent on how often the two states attack each other, as shown here:

NH = x, VT = y
x’ = -2x + y
y’ = x – 2y
x(0) = 2, y(0) = 1

“New Hampshire starts out with twice as many arms, which is to be expected because they have ‘Live Free or Die’ on their license plates…”

“So on the A axis we’ll plot tr(A). Stability occurs when both A and B are greater than zero. Say it’s like a relationship, where fear of commitment occurs when A<0, and one’s competitive instinct comes into play when B<0. So up here in the first quadrant we have a normal, stable relationship, and down here in the third… oh, I don’t know, it’s like when Jennifer gets fed up with Charlie and dumps him for Janine. Or Richard. Anyway, someone more exciting than Charlie. So, yes, you can find that down here.”

Mattuck’s lectures are legendary, and there are plenty of webpages with more quotes of his. Check them out!

More quotes
And look, another!

15 responses to “If the roots are imaginary, then the dots will be blue…”

  1. Funny!!

    Ankit Chandra
    Gaborone, Botswana

  2. Alice says:

    If only all our math classes were like that!

  3. Kate says:

    I love the funny qoutes! 18.03 sounds like a good time (well, as good as math gets, I suppose.) smile

  4. Kate says:

    I am so sorry that post came up so many times…I am currently having MAJOR computer difficulties.


  5. we need blogs like these for our class over the summer. It feels weird since the office of admissions is no longer our office. *sniff* But it’s still fun to read these. I’m currently just trying to make sure I don’t miss something important in the packet and online!

  6. Vytautas says:

    We have a physics teacher in our school who’s like that. If we talk about relativity then he has a joke about Einstein, if it’s Newton’s laws – he has one. And here’s his quote after one test: “It’s a good example how brain turns into porridge”. And by the way he’s also been teaching for 40 years.

  7. fed-up says:

    The one thing I would like to say is THANK YOU Ankit for not saying “First Post!!1!@!”

  8. Nixster says:

    Yo dat wuz funny!
    Anyone that has Jamaican roots are da bomb! Big up di country! …But none of my teachers are that eccentric,except one- it’s always the Physics teacher. Physics will make you -SICS…

  9. Hunter R. says:

    Haha! I love teachers with a sense of humor. It helps so much. not only by making the class not drag on so much, but a lot of the time…you learn more. PEACE!

  10. Ying Wei says:

    The quotes are so funny


  11. omorx says:

    Thanks for your blog, Keri G, for this blog.

    Could you please let me (or us) know what your strength was, in gaining admission to MIT. Was it your SAT scores, transcripts, essays or what? And what was your scores. This are things I really want to know.
    Thank you

  12. Dani '11 says:

    Thanks for posting quotes.

    I can’t wait to take that class!

  13. Omorx says:

    That prof must be a crazy prof.

    Emm, is there any guy from Nigeria in your school currently? I read there is someone from south Africa. I may have love to meet him or anyone from Africa.

    I’m from Nigeria

  14. I have a Math teacher at my high school who occasionally says the coolest quotes. My favorite ever is:
    “My house is not inside my house.” (when talking about set theory)

  15. Keri says:

    Omorx –

    There’s a guy in the class of 2008 who’s from Nigeria. As for your other comment, I can’t tell you for certain that any one thing – be it my essays, SAT scores, or anything else – got me into MIT. Email me at keri-lee(@)mit(.)edu and I’ll elaborate on that further.