************************************************************************* date: Mon, May 15, 2017 at 12:20 PM subject: Grades are posted on website, to be submitted soon I have posted course grades to a course website, see http://www-users.math.umn.edu/~adams005/MATH4604/distributioncourse.txt I plan to submit the grade to the registrar at the end of the day today (Monday), or, maybe, early tomorrow morning. If you have questions or concerns, it would be good if we could discuss them before grades are submitted. Feel free to contact me by email, or to call me at 612-625-5507. I plan to be around my office for most of the day today. Thanks. You've been an excellent class, learning a lot of very difficult material. Best, Scot ************************************************************************* date: Mon, May 8, 2017 at 1:05 PM subject: Final exam Hi, This message is to confirm that the final exam will be on Thursday 11 May, this coming Thursday, 1:30pm-3:30pm, in the regular classroom, Amundson 104. Between now and then, I will hold my usual office hours. Best, Scot ************************************************************************* date: Thu, Apr 13, 2017 at 11:28 AM subject: One more typo, in #48. Bill pointed out another HW typo, this one in HW#48: Be sure that the superdomain of g is equal to V, same as for f. I've fixed this in the HW, but, as usual, you may need to clear cache and refresh your browser to see the corrected version. Thanks, Bill. Also, a hint for #48: To show that a=b, one approach is to prove both a =^* b and b =^* a. When I write up my solution to #48, I think I'll probably do the work by proving first, that D_p((f,g)) =^* (D_p f, D_p g) then, that (D_p f, D_p g) =^* D_p((f,g)). - Scot ************************************************************************* date: Tue, Apr 11, 2017 at 3:38 PM subject: Change to #47 I made a couple of changes to #47, so please use the version online, and not the one from class. I forgot to bind the variable i. Also, it turns out that \partial_i ( f ( p + bullet ) ) might not be equal to \partial_i ( f_p^T ), because f(p) might not be defined, in which case f_p^T doesn't even exist. So I just took out all reference to f_p^T from the problem. - Scot ************************************************************************* date: Mon, Apr 10, 2017 at 10:50 AM subject: Office hours canceled on Th 13 April With regrets, I have to cancel office hours on Th 13 April. Class is NOT canceled. We will have class at the usual time. Best, Scot ************************************************************************* date: Mon, Mar 27, 2017 at 8:56 AM subject: Typo in HW#35 Sasha noticed a typo in HW#35. It shouldn't say ... = \emptyset. It should say ... = \{ 0_{VW} \}. I've corrected it, but you might need to clear cache and/or refresh your browser to see the updated version online. Sorry for the typo. Thanks for the correction. - Scot ************************************************************************* date: Fri, Mar 10, 2017 at 1:22 PM subject: Small change to HW#31 There was a small error in HW#31 that Bill noticed. I changed it, but you may need to clear cache and refresh your browser to see the new version. Thanks, Bill. Sorry for the mistake. - Scot ************************************************************************* date: Tue, Feb 7, 2017 at 3:53 PM subject: Homework hints First, I need to make a correction. --------------------BEGIN Let m,n \in \N. Let A be an n x m real matrix. Let u \in \R^m and v \in \R^n. Then B_A(u,v) is, by definition, the dot product of L_A(u) with v. --------------------END In class today, I started with this, then somehow corrected myself to write the dot product of L_A(v) with u. That makes no sense, because L_A : \R^m ---> \R^n, and v \in \R^n. Sorry. ======================================== In working the HW, you may use, without proof, the following fact: --------------------BEGIN Let m,n \in \N. Let A be an n x m real matrix. Let e_1,...,e_m be the standard basis of \R^m. Let f_1,...,f_n be the standard basis of \R^n. Then, for all integers i \in [1,m] and j \in [1,n], A_{ji} is the dot product of L_A(e_i) with f_j. --------------------END Pf: Given integers i \in [1,m] and j \in [1,n]. We wish to show that A_{ji} = [L_A(e_i)] dot [f_j]. By definition of L_A, for any v \in \R^m, the components of L_A(v) are obtained by dotting the rows of A with v. In particular, the jth component of the vector L_A(e_i) is equal to (the jth row of A) dot (e_i), The dot product of L_A(e_i) with f_j is equal to the jth component of the vector L_A(e_i), which is equal to (jth row of A) dot (e_i) which is equal to the ith entry in the jth row of A which is A_{ji}. QED ======================================== Remember that, for any vector u \in \R^k, by u^V we mean the k x 1 column vector with the same entries as u. (The "V" indicates that you should write the entries of u in a vertical way.) Here's another useful fact that you may use in the HW (again, without writing out a proof), if you want to: --------------------BEGIN Let m,n \in \N. Let T : \R^m ---> \R^n be linear. Let e_1,...,e_m be the standard basis of \R^m. Let i \in [1,m] be an integer. Then [T] is an n x m real matrix and (e_i)^V is an m x 1 column vector and their product [T] ((e_i)^V) is an n x 1 column vector that is equal to (T(e_i))^V. --------------------END Pf: For any matrix A \in \R^{n x m}, the ith column of A is A((e_i)^V). Thus [T] ((e_i)^V) is the ith column of [T]. By definition of [T], the entries in ith column of [T] are the entries in the vector T(e_i). If you put these entries into a column vector, you get (T(e_i))^V. Thus (T(e_i))^V is the ith column of [T]. Therefore, [T] ((e_i)^V) = (T(e_i))^V, as desired. QED ======================================== - Scot ************************************************************************* date: Thu, Feb 2, 2017 at 2:16 PM subject: HW typos, link to last semeter I corrected a couple of typos on the HW, so, if you've already printed out, I guess you'll want to reprint it -- sorry. Also, be sure to clear cache and refresh your browser, just to make sure you're getting the newest version. Also, to link to last semester's website, use the link in the *leftmost* column, at the bottom, that reads MATH 4603 last semester The URL is http://www-users.math.umn.edu/~adams005/MATH4603/ I won't archive that website until the summer, so it will NOT appear in the right column under "ARCHIVE". - Scot ************************************************************************* date: Wed, Jan 18, 2017 at 8:54 AM subject: Correction to HW In HW#3, I forgot the hypothesis that f be defined near a. That's corrected now, but you might need to clear cache and/or refresh your browser to see the new version. Thanks, Bill, for pointing this out. - Scot ************************************************************************* date: Fri, Jan 13, 2017 at 12:05 PM subject: Room change for MATH 4604 The classroom for MATH 4604 has been changed. It is no longer in Peik Hall. It is now in Amundson 104, on Tuesdays and Thursdays, 9:05am to 11am. The time of the class has not changed, only the location. See you on Tuesday at 9:05am in Amundson 104. Best, Scot *************************************************************************