Math110 Google Group

Re: Ch. 6 Homework Questions 5,6,7

kri...@gmail.com (Kenneth A. Ribet) — Tue, 21 Oct 2008 17:04:49 UT

It would be optimal if other students would chime in with comments.
The intention is that this was to be a discussion group, so I'll hold
off answering for a while... At least I won't comment on 5 and 6.
Nope. It's simply that people like to write complex numbers in the
form a+bi, with a and b real. However, bi = ib.

Ch. 6 Homework Questions 5,6,7

sherrygon...@gmail.com (Sherry) — Tue, 21 Oct 2008 07:41:08 UT

I just want to check some solutions and ask a question.

For number five, I want to disprove the statement.
For (a,b) in R^2,
+ |b|^2 = (|a| + |b|)^2 .
Since (|a| + |b|)^2 = |a|^2 + |b|^2 + 2|a||b| does not equal |a|^2 + |
b|^2 unless |a||b| = 0, then there is no inner product on R^2 such
that the associated norm is given by ||(a,b)|| = |a| + |b|.

Re: A Few Questions on Chapter 6

kri...@gmail.com (Kenneth A. Ribet) — Sun, 12 Oct 2008 14:50:46 UT

For complex n-space, the usual "dot product" formula for the inner
product is modified: you through in a complex conjugation. This has
the result that distance can be expressed in terms of the inner
product, as you say. In many linear algebra books, F can really be
any old field, and one ends up with a strange definition -- namely,

A Few Questions on Chapter 6

sherrygon...@gmail.com (Sherry) — Sun, 12 Oct 2008 09:37:00 UT

On page 99, it says that "we want to think of ||z||^2 as the inner
product of z with itself," but his formula for it looks like the inner
product of z with the conjugate of z. I wanted to know what I am not
seeing.

On page 104, I am having trouble understanding the proof of the Cauchy-
Schwarz Inequality where Axler looks at what ||u||^2 is equal to based

Re: Chapter 5 Problem 9

kri...@gmail.com (Kenneth A. Ribet) — Thu, 09 Oct 2008 13:47:29 UT

I don't think that the null space is necessarily of dimension 1. A
more fruitful approach to the problem is probably to think that many
eigenvalues require many eigenvectors and that those eigenvectors are
going to bulk up the range.
Ken R

Chapter 5 Problem 9

sherrygon...@gmail.com (Sherry) — Thu, 09 Oct 2008 05:55:35 UT

For problem 9, does anyone know how to prove that dim null T = 1?

Math 110, Fall, 2008

kri...@gmail.com (Kenneth A. Ribet) — Fri, 25 Apr 2008 22:16:12 UT

Former students,

I'll be teaching Math 110 this coming semester (Fall, 2008). If
you're getting this message, you might want to sign off from the Math
110 google group. Indeed, I might start using this group again for
online discussion and you might find that you're getting mail that
doesn't really interest you...

Re: Final exam paper available to pickup/look at?

kri...@gmail.com (Kenneth A. Ribet) — Fri, 20 May 2005 00:00:55 UT

I have 129 names on my spreadsheet, but two students somehow dropped
the course at the last minute. Two students had compelling reasons to
stop the course after the second midterm, so they're getting
incompletes. An additional 5 students didn't come to the final: one
student signed up by mistake and is trying to drop retroactively; one

Re: you know what this is about

mrjasonbol...@yahoo.com (Jason Bolton) — Thu, 19 May 2005 23:36:56 UT

Sorry Math 110 mailing group, I meant to send that to
jvoight@berkeley! _ jason

you know what this is about

mrjasonbol...@yahoo.com (Jason Bolton) — Thu, 19 May 2005 23:15:41 UT

John, I'm probably the zillionith customer, but could
you please email me as many of the following that are
not inconvenient to calculate:

1.) my grade on the final
2.) final grade in class
3.) mean on the final

Thank you very much, have a great summer! - Jason

Re: Final exam paper available to pickup/look at?

mariota...@gmail.com (mariotanev@gmail.com) — Thu, 19 May 2005 23:02:29 UT

Is there a way we could see the distribution of points on the final
exam?
Thanks

Re: Final exam paper available to pickup/look at?

kri...@gmail.com (Kenneth A. Ribet) — Thu, 19 May 2005 21:03:52 UT

The exams have been graded, and we have assigned a final letter grade
to every student. Before we enter the grades, the GSIs are looking
through the spreadsheet to see how many errors I made entering data.
The GSIs currently have the exams. If your GSI is around and you find
him, he'll quite possibly be willing to show you your exam. If you

Final exam paper available to pickup/look at?

eunicech...@berkeley.edu (Eunice Cheng) — Thu, 19 May 2005 20:53:09 UT

Will the final exam papers available for students to pick up or look
at? If yes, when? :)
- Eunice.

Re: random pre final questions

kri...@gmail.com (Kenneth A. Ribet) — Wed, 18 May 2005 21:35:48 UT

Endorphins?

-ken r

RE: random pre final questions

d...@danacland.com (Dan Acland) — Wed, 18 May 2005 21:18:15 UT

Of course we understand that it is conventional pedagogy to arrange for the
students to panic after they see the actual exam. Thanks for the adrenaline
Dr. Ribet. =;)

Dan.