Professor Richthammer was a very caring teacher but at the same time he was awful at presenting topics to those of us who had not taken calculus already. He was more concerned with the proving of obscure topics than getting to the basics and helping people who were learning the subject. Every week I would have to spend hours daily in the tutoring lab just to finish the homework and barely pull a B- on average. To top it off his midterms and finals were ridiculously hard, making it almost impossible to succeed even if you try your hardest. I wish him the best, but do not take him unless you want to be miserable.
Professor Richthammer's 31B was my first math class at UCLA so I didn't know what to expect. I thought he did a great job teaching up until around the 6th week of class. After that the material just gets more and more confounding and I think he tried his best to clarify it for us. Homework was a lot of work. Nine homework assignments due every Friday (drops lowest 2 if I remember correctly). He wrote his own problems (we never used the book) and so there were definitely challenging questions. He does his best to explain anything you don't understand if you go to OH or if you email him. The two midterms were pretty straightforward. I thought his grade curves were justified. The final was a monster. It was originally out of 120 or so but he set the total to 85. Even with that the class average was a 59%. It's a challenging class and the material isn't easy, especially the first time around, but he's overall a good professor. If you're planning on taking him for 31B, all I can say is make sure you do the homework in its entirety.
Professor Richthammer is a really good professor. He really understands what he's lecturing, and does a good job balancing theory with examples. For lower-division classes, I could imagine him putting in more theory than is necessary, but once you hit upper-division classes, you should expect to get theory no matter what. His homework and tests are difficult, but he is a very generous grader. I struggled through the class, and still managed a B-, which I personally thought was higher than I should have received. He is also extremely approachable, encourages you to ask questions, and can be reached at office hours or via email very easily. Overall, he's a good teacher that will push you to understand the material, while not grading too harshly at the same time. Highly recommended.
Professor Richthammer is extremely organized and very clear in speech. His lectures are rather fast paced, but he speaks very clearly and encourages participation from the class. He writes all of his own problem sets, which are very challenging. However, you get a clear understanding of the material by completing the homework on your own. He never gives out answers during office hours, but gives hints to help guide students along. Basically, it's pointless to go to office hours if you haven't already tried the problems. His tests are challenging and requires a clear understanding of the material, but he curves very generously. My scores on two of the tests were over 100% after the curve. He also curved the class one more time in the end according to math department standards, which yielded quite a few A's. So overall a difficult class with relatively easy grading.