## Friday, November 12, 2010

### Study Buddy

I just finished helping my daughter study for a proofs exam.  Why? Because I was too tired to come up with an excuse for why I couldn’t help her study.

My job as study-buddy is to hold up a flashcard and nod as she recites drivel to me.  If the drivel is vaguely related to what is scrawled on the card, I say “good.”  If the drivel seems unrelated, I say “yeah, maybe.”  Then she looks at the card and says, “That’s exactly what I said.”  And I say, “Oh, right.” I mean how am I supposed to know that a sideways swirl is actually an “R,” which isn’t really an “r” but is actually a “relation?”  (Maybe they’re second cousins once removed, but I didn’t ask.)

However, I did find a couple of interesting things like hUg.  Any math that involves hugs can’t be all bad.  And actually hUg stands for “h” union with “g” so it really is a kind of hug.  Which leads to the integral of e to the x, but I won’t go there.

There are other cool terms we studied and here’s what I think they should mean: supremums (super mums—moms who sacrifice their “down” time to help their daughters study) and infimums (sick mums—moms who stay up too late helping their daughters study).

Then there’s the set theory thing with inverse images. I told her they looked like paramecium.  She was mildly offended that I’d “managed to taint” math with science.  Hmm. I’ll remember that for next time I want to get out of flashcard duty.  “Hey, Ar, the foot of this swirly R looks like a flagellum.”

1. The stuff she is studying makes my brain hurt.

2. If you asked my husband he would say Science is Math and vice-versa. And it's true flagellum; a flagellum does have a tail. Err, thanks Google.

3. @_@

Okay...Ariel can have all those sideways rs that she wants..I won't be needing any...:0

4. How about function of F multiplied by function of G? F o G? It's so thick, I still don't quite understand it.

5. Andrew--

Yep, she's learned the proofs for FoG, which is actually GoF. Don't ask me why, I have no idea although the intricacies of it were explained to me last night.

6. This post was so great.
Don't forget the "fatimums" which are the fatigued moms always tired, not to be confused with the "fattimums" with are the moms who finished all their kid's Halloween candy.

7. Oh, and I'm probably both types of mums, btw.

8. Lydia-

My daughter's going to love that. Thanks!

9. I'm study buddy to three of my four and some days it literally puts me to sleep!

10. Lol -I'm not there yet with my kids, but this was a very amusing post!

11. In my universe of discourse FoG is "Form of Government". I'm worried. When we see Ariel next will we be able to understand each other? Will there be a translator?

12. Oh, I can never understand Ariel, even when she is speaking English. And when she tries speaking Spanish. . .

13. Wikipedia tells me that GoF is the "General Operations Force," which is apparently a branch of the Royal Malaysian Police. Who would've thought?

14. Andrew-

Ariel's been uttering math imprecations since she's read how much math has been botched on this post. :) Maybe she'll explain it to us. Or maybe not. When she explains it tends to drone on and on and use words that have no meaning to me. And I end up more confused than I started.

15. Hey, Luke, you're the one who tries to speak Spanish; you're the one taking it, not me. I don't need a foreign language--I have math :D

GoF and FoG are compositions of the two functions F and G, and they actually have different results. My professor likes to have us do FoG because she loves math problems that make words.

16. F(G(x)) is FoG, right?

17. Oh dear god my brain just exploded.

ficklecattle.blogspot.com

18. You're right, Andrew. F(G(x)) is FoG, which we get to use if we're working problems with FoG.

For proofs with FoG, we have to define FoG in terms of relations on sets:
For functions G (from set A to set B) and F (from set B to set C) the composite of G and F is the relation from A to C: FoG = {(x,z)∈ AxC: (x,y)∈ G and (y,z)∈ F, for some y ∈ B}

This has been a pretty fun class. There's nothing like having to prove why something works to help yourself understand it.

19. A lot of the time, you can just memorize what algorithm they throw at you, but it's always best to slow down and understand why the function works.

Or at least that's my experience.