Wenjian Liu

Homeworks were insanely easy, could finish in < 30 min or at most 1 hr. Lectures are optional, there wasn't much discussed that actually helped on exams. If you must take this class, which I don't recommend, be prepared to teach yourself and make sure you know how to write a good proof.

Follows the textbook very strictly - Further Mathematics for Economic Analysis

Easily one of the worst experiences at Columbia, mostly due to the professor. Lectures and homeworks were incredibly easy but exams were terrible. Many or most of the questions on the exams are (as another reviewer put it too) computationally impossible or crazy proofs that were never taught in class. The worst part is that grading on proof questions was harsh as well. Cheating on exams was rampant and I knew several people who copied, inflating the midterm exam averages. Prof seems nice but is not understanding at all about health issues regardless of documentation or advisor support. Unless you're a proof god, avoid.

Learned some basic optimization problems, convex/concave spaces, then the rest was a review of ODE's.

7 homeworks, lowest 2 dropped (20%) 2 midterms, lowest dropped (40%) Final (40%)

Linear algebra, calculus, optimization, ODE's

Wenjian seems like such a nice guy, but then his midterms and finals are super devious. The homeworks took no time and his notes are written in LaTeX and are so easy to understand. But understanding his notes will likely only help you do like, 60% of the test. The rest? You're on your own, probably sweating and being annoyed because he's sitting at the front of the room laughing at his show on his iPad. He's really nice when you ask him for help for homework, but his tests are just a different demon and he'll laugh if you're doing something wrong. He literally went around leaning over people and then laughing if they were doing something wrong. He gives you 2 front & back cheatsheets for each midterm, 4 for the final. He let our class drop a midterm because everyone ate balls on at least one of them. First midterm average was 69%, second was 80-90% (this is likely attributed to a diabolical amount of cheating and copying), and 72% on the final. This curve should be delightful though, I hope.

Review of linear algebra, Optimizations techniques including LaGrange multipliers, Basics of ODE, Calculus of Variations

Biweekly homework (20%), two midterms (40%) and a final (40%). Homework was incredibly easy, midterms were okay, and final was awful.

Explore various approaches to optimization problems useful in economics and the physical sciences.