Homework 2 / grapes

Yeah so the assignment is up it’s been up for a little while so maybe you’ve seen it already but maybe you haven’t but in any case it’s there in the Assignments tab right where it should be and the solutions to the first homework are up there too so have at it. 


Review problems / chortles

Dear y’all,

I’ve posted some review problems in the Documentz tab. The solutions to hw 10 are also there. Also, I have posted a drawing of a giant squid battling a sperm whale, with a couple of sharks swimming about nearby. Do with that what you will.

I will go over some of the review problems on Tuesday, but bring any other questions or concerns you have about any of the material from this part of the course. If we have extra time I’ll probably just rap the first verse from “Get Down” by Nas, so come prepared to prevent that eventuality.


Homework 6

The assignment is this:

Section 3.2: 24

For the matrix in #22 of section 3.2: For what value of k does the system have no solution?

Section 3.3: 2af (you don’t have to follow the examples — just find the inverse, or else justify why no inverse exists), 7acf, 8acf, 9a (for the matrices in parts a, c, and f of #7), 18, 20, 24

Also: Prove that (AB)-1 = B-1A-1

Due: Thursday, 27 March 2014, in class.

Please staple your homework. Please remove ragged edges from pages torn from notebooks. Please hand in homework at the beginning of class or at the end — not during lecture. 

I forgot to mention in class that another reason why that spot The Beach in New Orleans is near to my heart. You know how every American over 55 or so remembers where they were when they heard that President Kennedy had been shot? Well, The Beach is where I was when I heard that Nate Dogg had died. The DJ slipped it in between cuts — “Yo RIP Nate Dogg” — and my friend (who’s from Long Beach, so you can imagine how hard the news would be for him) and I looked at each other incredulously, checked our phones to confirm the news, then poured out some of our drinks in silent remembrance.

Since I told you I’m going to Seattle next week, here’s a few hot tracks from Odesza, a duo who hail from the Emerald City (and this remix, which reminds me a bit of “Better Off Alone” by Alice DeeJay, which most of your should be old enough to remember, I hope).

One of Diego Velázquez’s best works (and that’s really saying something, as some (including Manet) believe he was the greatest painter of all time) is the Portrait of Pope Innocent X, which is the masterpiece of the Doria Pamphilj Gallery in Rome. It’s also one of the greatest potraits of all time. Legend has it Il Papa said upon viewing it “E troppo vero!” (It is too true!) but that might be apocryphal:


The collection is among the world’s finest in private ownership, and the palazzo that houses it is one of the grandest. There’s an interesting Pamphilj inheritance battle that was detailed in a Vanity Fair article that came out late last year. (I have the paper copy in my office if you are into physical artifacts.)The short of it is that Jonathan Doria Pamphilj, one of the two heirs to the massive estate, is married to a man, with whom he has two children who were born by surrogacy. Jonathan’s sister Gesine Doria challenged the two children’s right of inheritance based on the fact that they were born of a surrogate. The case was thrown out without a ruling, on the grounds that Princess Gesine (of course she’s princess) didn’t have grounds to bring the suit. In an interesting twist, neither Gesine nor Jonathan themselves are in fact Pamphilj by blood; they were adopted almost five decades ago from England by Orietta Doria Pamphilj, who was at the time the sole heir to the estate.

The great 20th-century Irish painter Francis Bacon (not to be confused with the English philosopher/statesman/scientist Francis Bacon, who was one of the most important proponents of the scientific method, and in 1603 became the first scientist to receive a knighthood) was greatly inspired by Innocent X, and created a number of works that engaged directly with Velázquez’s masterpiece, including this funky rendition:


Bacon was perhaps even more influenced by Sergei Eisenstein’s film Battleship Potemkin, particularly this face, seen during the famous Odessa steps sequence, which appears and reappears in various forms throughout Bacon’s oeuvre:


Brian DePalma paid homage to the Odessa steps in The Untouchables; more hilarious is the parody of DePalma’s scene that opens The Naked Gun 33 1/3: The Final Insult. RIP Leslie Nielsen.

Incidentally, Francis Bacon’s triptych Three Studies of Lucian Freud recently sold for $142.4 million, a record price for a painting at auction.


Lucian Freud (grandson of Sigmund) was a pretty brilliant painter himself:


Though he caught some grief (for some reason, I distinctly remember this article (or at least the Daily Telegraph quote within), even though it was 12+ years ago and I’m sure I’d never heard of Lucian Freud at the time) for this portrait of Queen Elizabeth II:


“Troppo vero”, indeed.

“Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you’re a mile away and you have their shoes.”

Exam 1 solutions

The solutions to exam 1 are posted in the Documents tab. They’re JPEGs because the department photocopier wasn’t working earlier when I went down. Hopefully it will be up tomorrow and I can replace the pictures with scans.

Your next homework will be due on Thursday, 13 March 2014. Here’s the assignment:

Section 3.1: 24(i), 28, 34

Section 3.2: 3abcd, 4abcd, 8, 9ab, 12, 20

Your next exam will probably be on Thursday, 3 April 2014.

We’re going to grade the exams tomorrow, hopefully we’ll finish up and get the grades on Blackboard by the late afternoon. 

If you’re bummed about the exam, you should watch some Kyle videos to get your spirits up.

If you’re into True Detective, you should watch director Cary Fukunaga’s debut feature film Sin NombreIt was on Netflix Watch Instantly back in the day, but isn’t anymore; you’re enterprising college students, though, so I’m sure you can find a pirated copy if you’re not about paying for stuff.

Manchego cheese comes from sheep, not goats. Come on guys. Goat’s milk cheeses are usually brilliant white, like Monte Enebro:

monte enebro

Monte Enebro has the added benefit of figuring prominently in one of my best freestyle verses:

Other rappers they can chase that cheddar
That ain’t enough, I know I can do better
Gettin at that Pont l’Évêque and the Monte Enebro
Just turnin one into two like Serbia and Montenegro

It has all three classic hip-hop references: fine cheeses, geopolitics, and hustling.

“If you ever fall off the Sears Tower, just go real limp, because maybe you’ll look like a dummy and people will try to catch you because, hey, free dummy.”


Homework 2 – clarification

For problem number 17 in section 2.4, the vector b is a column vector. The reason for this is because the entries are separated by commas rather than just spaces.

This is done in order to preserve uniform line spacing in a paragraph. I think I may have mentioned this in class but I’m not sure.

Before he was a grizzled old Obama-chair-hatingPBR-swillingOscarwinning curmudgeon, Clint Eastwood starred in many of director Sergio Leone’s spaghetti westerns. They’re some of my favorite movies ever, not least because of Ennio Morricone’s brilliant scores. The theme from The Good, The Bad, and the Ugly is, of course, the most famous, but there is a lot more to his work. A Gringo Like Me is a pretty fun song that enjoyed a slight bump in popularity after the Lonely Island dropped it in their criminally underrated film Hot Rod. And I’ve always loved the pocket watch theme from For a Few Dollars More; the tune is good on its own but absolutely brilliant in the context of the film, which is tighter and leaner than TGTB&TU, if not nearly as epic and awe-inspiring.

Anyway, the reason I’m thinking about Sergio Leone movies is because of this incisive piece of commentary from Jack Handey:

“If you’re a cowboy and you’re dragging a guy behind your horse, I bet it would really make you mad if you looked back and the guy was reading a magazine.”


Exam 2

Hello class,

 As you know, your second exam will take place this coming Wednesday, 23 October 2013, in class. No graphing calculators will be allowed. The exam will cover material from:
Section 3.1: Determinants: Calculating them, using them to solve systems of linear equations, knowing their properties including special cases in which the determinant is easy to calculate, using them to find eigenvalues and eigenvectors, using Cramer’s rule.
Section 3.2: Solving systems of linear equations by elimination: Gaussian elimination, row echelon form, three possibilities for a system: (i) a unique solution (ii) infinitely many solutions (iii) no solution. Finding LU factorization of A aka LU decomposition of A and using it to solve Ax=b. Elimination by pivoting aka Gauss-Jordan elimination.
Section 3.3: Inverse of a matrix: Definition of an inverse, how to prove one matrix is the inverse of another (use the definition), what does it mean when the matrix has an inverse, computing the inverse, properties of the inverse. Eigenvalue decomposition of A aka diagonalization of A — what is it, how do you do it, why is it useful (study carefully pp. 204-207 of the text).
Section 3.4: Iteration: Determining dominant eigenvalue and corresponding eigenvalue by iteration (Example 2 on p. 216), solving Leontief model by iteration using properties of the geometric sum (Example 4 on p. 221, and the preceding analysis). Solution by iteration (p.223). Rewriting Ax=b to be in form x = Dx + c (sometimes c = b, sometimes not — see Example 5 (which we did in class)). Theorem 3 on p. 230.
 Everything I did in class that’s not in the textbook is also fair game. Specifically, you should know that theorem I presented on 9 October with a whole bunch of conditions that are equivalent. I neglected to name it when I presented it, but I will call it … the Fundamental Theorem of Invertible Matrices.
Come see me in office hours on Tuesday, and take advantage of the TAs’ hours as well.
For practice, you should review carefully all the examples I presented in class, redo the homework problems (without reference to your previous solutions, my posted solutions, or the textbook), and do similar problems in the textbook. Like these:
Section 3.1: 1, 3, 5, 7, 17, 20, 23, 27
Section 3.2: 3ef, 4ef, 5, 9c, 15 (also by pivoting), 22
Section 3.3: 10, 19, 21, 22, 25, 29, 31, 32, 33
Section 3.4: I haven’t yet decided how exactly I’m going to test your knowledge of this part, since a lot of the implementation of what’s going on here requires a computer, but study the examples closely. Exercises: 7, 8, 13b, 14
You don’t have to do all of them because that would take a while, probably. Just make sure you feel like you could solve them all.
You should check out this album I’m listening to right now, I’m not going to say the name of the band because it’s got an obscenity in it but if you can get over that fact the album is called Slow Focus, it’s tight.
How great is Jaleel White’s face in this poster?

Clarifications / Exam 2


Two things from class today:
1. The plural of wunderkind is, of course, wunderkinder. I realized as much right after class, (when I thought about the word kindergarten; I also remembered a sentence in a book I read long ago: “eine Schande für die Kinder” (or something like that), which a German woman says to her husband (in a pleasant way) when he is affectionate with her in front of their children. I don’t remember what the book was, though, and Google didn’t help, so if you happen to have the same weirdly specific memory and know whence that sentence comes, PLEASE let me know because it’s bugging me). Coincidentally, I was listening to the piano quintet in B minor by the German composer (and Beethoven chum) Ferdinand Ries when I realized wunderkinder was the right word. I suspect the Germanness of the piece helped me out quite a bit.
2. It’s “Rayleigh coefficient”, not “Raleigh”; I think I wrote the latter name on the board today. (Note: I put the previous sentence’s comma and semicolon outside the quotation marks, in the British style, because Lord Rayleigh was English (I also thinks it makes more sense to write that way)). Lord Rayleigh won the Nobel Prize in Physics, for discovering argon, but is perhaps better known for Rayleigh scattering, which explains why the sky is blue (it’s because it’s been listening to Miles Davis’s soundtrack to Ascenseur pour l’échafaud).
Perhaps more importantly for you, the second exam will be 23 October 2013 (one week from this Wednesday) in class. It will cover chapter 3. I will be more precise with respect to what exactly you need to know sometime after this Wednesday’s class. Don’t forget to do the homework that is due this Wednesday.
Robert Mapplethorpe was a hugely controversial photographer, but he also once took this lovely picture of bread:

Homework 4 / exam 1 / office hours

A number of items on the docket for this email:

– The complete homework 4 assignment is posted in Assignments
– I made a mistake in my solution set for the exam, in part (a) of question 3. The correct answer is that the population after 3 months can be at most 8 times the current population, not at most twice the current population. I’ve just updated the solution set on Blackboard. I’m very sorry for my carelessness. 
– I’m not sure whether the grader caught my error, so if you were unjustly marked wrong on that problem come see me and I’ll change your grade accordingly. If you were unjustly marked correct, keep the points — my treat. If you have other issues with grading come see me — particularly if you were docked an excessive amount of points for a small arithmetic error. My rubric calls for only one or two points off (usually — maybe more depending on where it occurs and how egregious it is) in most cases of small calculation errors, so if you lost 8 points for a very small mistake you might be entitled to some of the points back. Please understand that it is difficult for the grader to follow your calculation through to see if your mistake was purely calculation-based or representative of a more grave shortcoming of yours (especially with ~115 exams to grade), so try not to get too frustrated.
– I’ll be in my office from 3:00 – 5:15 pm tomorrow (Thursday 3 October) to deal with exam grading issues. If you didn’t get to pick up your exam in class today, you can get it then. You can also come by next week — after class on Monday or during regular office hours on Tuesday.
– If you’re feeling down about your exam grade, watch some Monty Python sketches. That’ll cheer you right up. If you’re feeling good about your exam grade, read some news articles. That’ll sadden you right down.
– R.I.P. Tom Clancy. I was not a big fan of his, but a lot of people loved his work, so big ups to him.
– The kouign amann is a buttery, caramelly pastry from Brittany, France. It is really tasty. I made this one:
from a recipe by David Lebovitz that you can find here. You can buy them from Dominique Ansel (maker of the cronut) in NYC.
tl;dr – Come on, there’s no tl;dr. Just read the damn email. (At least the first, math-related parts of it.) Gee whiz.

Exam 1 will be Wednesday the 25th of September, in class

As announced in class today, the first exam will take place on Wednesday, 25 September 2013, during the usual class time (8:30am) in the usual classroom (Humanities 1003). The test will cover all material from the beginning of the year up to and including today’s (Wednesday, 18 September) lecture. You will be tested on concepts as well as techniques, so make sure you understand the ‘why’ of everything, not just the ‘how’.

What we’ve done:
– Mathematical induction
– Transpose of a matrix, symmetric matrices
– Section 1.2 (systems of linear equations)
– Section 1.3 (Markov chains, dynamic models)
– Section 1.4 (linear programming, over- and underdetermined systems)
– Section 2.1 (matrices, vectors)
– Section 2.2 (matrix multiplication)
– Section 2.4 (matrix algebra)
– Section 2.5 (norms and bounds, eigenvalues and eigenvectors)
There is no homework this week.
If you’re nervous about the test, just think about how nice-looking cooked mushrooms can be:
And check out that cheese!
Feeling better, right?
Unrelated to the exam: wheat scenes from Love and Death can be found here and here