Nothing, this man is such a good lecturer. He is from Kangaroo Island which is dope. Really nice dude and overall chill dude. Lot of content to go through though. And his tests were 50/50 application of theory and computation.

I had Arnold for Math 32A and I loved having him as a professor. He comes off as kind of shy and quiet but he's very funny and does a fantastic job of explaining the material. Both midterms were fairly easy and the final had two "curve-setting" questions that were difficult for most people. His homeworks are also really short (3/4 problems per week) but they make you think about the material in a critical way. Overall, I definitely recommend Arnold as a professor, but make sure to put in a lot of effort to do well.

Arnold is pretty cool as a professor. His lectures are informative and cover the necessary material, and he is pretty clear with all of his explaining. Also has an Australian accent as a bonus. He makes his own weekly homework assignments, which are basically three very challenging problems that will take several hours. The midterms are pretty straightforward and not too hard to do well on, provided you don't make any calculation errors. The final fucked me up the ass real good though. He also curves the end grade very little, if at all. So basically, he's a cool dude, but getting an A in his class is very difficult.

David Arnold was a great professor for 32A. He gives short homework assignments that help you better understand the material, gives engaging lectures, and Bruincasts all of his lectures. It is clear that he cares a lot about his students learning and understanding the material. Both midterms test you more on pace and are more computation-based, but the final has less of a time restraint and requires more conceptual thinking on a few of the questions. I definitely recommend him as a professor.

This class was a grind. I thought Arnold was a fantastic lecturer and I learned a whole lot from the class even though I had previously taken a multivariable calculus class. He was clear and to the point. However, his tests were notoriously difficult, especially the final. Inadequate preparation meant I didn’t finish the test, but every problem was solvable within the time limit. I finished both midterms on the other hand. Although it’s not an easy A, I can’t recommend this professor enough.

The workload is not heavy since there's only 3 problems each week. Arnold is a good lecturer and his lectures are well managed. The exams are not that difficult and definitely doable. Highly recommended.

Professor Arnold is a really nice guy and he puts a lot of efforts into teaching. He genuinely cares about his students and he is really helpful during office hours. His lectures are engaging and he has a good sense of humor. He doesn't do many examples in class and most of the time, he just goes over the definition/concepts. I wish he did more examples in class. He covered dimensional analysis, perturbation theory, traffic flow and population theory. Since he doesn't do many examples in class, I definitely spent more time on my homework. I guess 142 is not an easy class and you really need to put in more efforts. Wish I realized that before my final :( Overall, it's a good class and you will learn a lot from it.

David Arnold makes this class infuriating. His lectures are pretty good, and his homework / midterms are pretty easy, so when teacher evaluations came around all my friends rated this guy pretty highly. He's a bit introverted but seems like a really sweet guy during lecture, and the concepts in 32A don't seem that difficult. However, he has this insane grading policy where the final is 70% if you do bad on one of the midterms, and the midterms are really easy to mess up since they are only out of 20 points, and if you make one mistake on a problem you are pretty much doomed. Right before the final, the class difficulty began ramping up, and when he gave out this ridiculously hard final review sheet I knew something was up.

My fears were confirmed when this dude whips out an insane 3 hour long final with a bunch of random proofs using the chain rule for paths (we talked about this for like 1 second in lecture??) and then makes the final 70% of most people's grades, and doesn't release statistics / gradescope for the class (I think the average would be below 60%). Compared to the midterms, the final was unreasonably hard, and I know most people who felt like they should have got an A got an A- since Arnold doesn't curve the class, and only gives an A if your raw score is above 93. I got an 80 on the final, and ended up with an A- (saved by the math dept policy of top 30% of the class getting an A-). If you take this class with Arnold, just make sure you don't underestimate the final, and be prepared to study a lot for it. He's not a bad professor, but I wish he used gradescope + gave out practice finals / other prep + used piazza + any other form of communication with students. Overall, I'm not sure I would have taken this class with Arnold again, because although he is a decent lecture, he doesn't really give many resources for students to succeed in the class.

Great guy with an awesome accent. The class was a natural step up from high school calculus and nothing was too difficult. Homework accurately represented the tests and the online quizzes weren't hard.

I really enjoy Math 32A with Professor Arnold. His lecture was clear and the workload was light. He only gave 3 hw questions each week. None of these questions came from the textbook, but they covered the important concepts very well and deepened your understanding of the concepts.
His midterms were quite easy, but the final was definitely hard. Still, I managed to score pretty well in his final by going through all his practice problems and all the pass exams on the bruin online testbank. Just do tons and tons of practice and make sure you understand all the concepts very well, because his final was more conceptial and proof-based compared to his midterms.
Overall, if your major requires lots of mathematical skills or you want in-depth understanding of multivariable calculus, I'll recommend Arnold. If you want an easy A or just don't want to put too much effort into math, don't take Arnold, because his final is definitely gonna screw you.