Monday, October 31, 2005

Happy Hallowe'en!



My, Earth really is full of things.

Saturday, October 29, 2005

HW #5

Sorry for the delay. I really do mean to get these out on Friday, not Saturday (or later!). Happy Hallowe'en.

2.1 #1,8,9,10,11
2.2 #1,2,5,10,13
2.4 #2,3,6,17,18

I'm turning comments off

Not that more than two or three people care (and spambots), but it's probably better that I turn off comments, otherwise I give the false impression that it'll occur to me to read them. If you have questions, email your TA and me.

Wednesday, October 19, 2005

No Maia 1 PM office hour Oct 20

As the title indicates.

How embarassing!

While sleepily writing up the answers I dropped a factor of n in the question involving sin n. (Don't worry, we didn't grade using that as an answer key.) The corrected version is up now.

Part of HW #4

This is due Oct 28, nine days hence. I will probably add a couple of problems based on what we do Friday.

1.1 #14,15,16,17
1.2 #1,2,7
1.3 #1,2,3,4,14,20,23

Midterm #1 answers and curve

The answers to midterm #1 are here.

Here's the curve (do read below for what this means):
0-20 F
20-30 D
30-40 C
40-50 B
50+ A

Yes, it was a hard exam; no, it wasn't that hard to get an A on.

The final grade will not be computed by averaging letters together. It will be computed by adding up numbers (book HW + Matlab HW + midterm 1 + midterm 1 + final).
If we say "40 was a B on midterm 1, 60 was a B on midterm 2" etc. and you get B,B,B,B,B then you'll get a B.

People ask "Is there hope for me to pull up my grade?" Absolutely! This is a very important benefit of having the numerical grades closer to 50 than to 90 -- there's much more room at the top. If the averages are 95 and you get 60 on one test and 99 on the next, the 99 doesn't help much. If the averages are 20 and you get 0 on one test, the second test gives you a lot more chance to get back on top.

Monday, October 17, 2005

Definitely back by Friday

We haven't finished the grading yet (Monday night), but we will definitely be returning the midterms Thursday, before Drop Day on Friday. (That was part of the reason for having a midterm so early.)

Saturday, October 15, 2005

A note from the homework grader

On the midterm, I'm going to try my hardest to be very specific about what constitutes a complete answer, even moreso since people have been asking me about homework grading.

This is what the homework grader has to say about it:
"Here is what I like to see.

1. If a theorem is used, it should be cited (especially with
convergent/divergent series problems since there are so many tests).

2. Non-trivial integrations (especially ones by parts) can't be omitted.
For example, f(x) = ln(x)/x^2 from the last hw. They can't just write
Integral(f(x)) = -ln(x)/x - 1/x with no intermediate steps.

3. In general, when in doubt, show the work.

Those are the main things for me. Stating theorems and showing work."

Some book questions to help prepare for midterm #1

We had homework on sections 11.1,2,3,4,6,8,9,10.
We discussed some of the material from 11.5 (alternating series) and 11.7 (strategies for testing for convergence) in class; you should know these too.
11.11, 11.12 you can ignore (for now, at least).

Sequences aren't as important for us as series, especially power series, so pay more attention to the later sections.

Basically, you should be able to do any question in 11.7, and at least one of these will be on the test.

The questions 11.8 #3-28 are another good group to be comfortable with.
#29 is tricky and you should be able to do it. The only way to answer a "If you know A, does it follow that B?" question with "No" is to say "No; here's a series for which A is true, but B is not true." If all you say is "I don't see how to get B from A" you leave open the possibility that someone else might. This is one reason it's worth memorizing examples of weird behavior.

11.9 #9,10,15-18,38. (This last one's a little more work than you'll actually see on the test.)
11.10 #3-18. For Taylor series centered at a different from 0, you evaluate derivatives at a instead of 0. Know your sin from your cos!
#23-32 are good too; you should be able to plug in, multiply, differentiate.

Friday, October 14, 2005

Some stuff about midterm 1, coming Monday

Turn off your phone.
No books or calculators.
Don't bring a blue book.
One double-sided sheet of handwritten notes.
Turn off your phone.
Material only what's been on the homeworks so far or discussed in class (e.g. alternating series).
Please raise your hand and ask questions during the test if you need to!
I'm hoping for an average of about 60/100, so that grades aren't assigned based on random fluctuation. So once you think you got half, breathe easy!
No really gross integrals. Some basic limits. I don't want it to be a speed test.
Turn off your phone!!!

I will post a big list of study problems tomorrow before noon.
Basically a bit of sequences, more about series, some Taylor series stuff.

Sunday, October 09, 2005

HW #3

Look at 11.7 for more practice with convergence vs. divergence.
11.8 #3,8,9,10,35.
For this you need the "interval of convergence". We didn't discuss this in class -- it just means, find the radius of convergence, then test what happens at x=R and x=-R. (I.e. whether they should be included as the endpoints of the interval of real numbers within the radius of convergence.)
11.9 #7,8,14,35
11.10 #7,8,9,10,27,28