This was his first class at UCLA, so he definitely wasn't the greatest lecturer, however, he was clearly very caring for his students and could be quite funny during lectures. His exams were extremely straightforward and I did well up until the final which I hardly studied for and rightfully did terrible on, which dropped my grade from a comfortable A to barely a B. Overall, I only expect Haoren to get better as a lecturer and I would definitely recommend him for this class.

Underrated in my opinion. He goes through material in an efficient and clear manner, and releases homework every lecture (just a few questions). Furthermore, his lectures (at least during fall 2022) were recorded, so you didn't have to attend lectures physically at all. His practice midterms are extremely similar to his actual midterms, so I would recommend doing them.

Overall, I have found this course to be very enjoyable and informative, and Haoren is an excellent lecturer who explains the material very clearly. I especially appreciate that he provides helpful notes that are useful for reviewing, and that he always uploads the lecture recordings on time. Based on my experience, I would highly recommend him for 31B.

However, I did find the final exam to be quite challenging, even though I thought I had prepared well and was hoping for at least an A-. Unfortunately, I ended up with a B+ instead. On the other hand, the midterms were much more straightforward and closely resembled the practice exams, so I found them to be manageable with sufficient preparation. For anyone planning to take this course in the future, I would suggest being aware that the final exam may be more difficult than the midterms, and taking extra time to prepare accordingly.

This is his first lecture ever taught, and I'm surprised by how fast he improved his style of lecturing. His exams weren't the easiest, but if you study hard you will end up with a good grade. Definitely would take another course with him.

Honestly, you are just teaching yourself everything. The professor reads and explains very poorly actually he does not explain. The exams he makes are very complicated and include things that he does not even go over, which is very frustrating. When the class does badly, he writes a message to the students about how badly we did. I took him last quarter too for 31 AL and he said "I went through this and suffered now it is your time to suffer" just to show that he does not care.

Haoren is a kind person and I think it is possible to do well in his class. I took this class my first quarter here and his first quarter at UCLA. I came in having done well in AP calculus AB (I got a 5 on the exam and did really well in the class). The content's logic level was similar to the material from calc AB(and I assume 31a). However Haoren's teaching method was very difficult to understand--I do best when I am plainly told which methods to use for which problems. In each class, Haoren simply started solving different problems while vaguely narrating each step with out explaining why. It felt like he was reading from the textbook. When students asked questions, he would give a quick response and then keep solving without checking to see if his explanation made sense. Sometimes when people asked him why he was doing something, he would say, "this is just what the textbook says". My TA, Zerrin Vural was great. During discussion, she would explain things in a way that made much more sense to me! Also each lecture was very similar to the textbook, so towards the end of the quarter, I started reading the textbook before lecture which helped a lot. The lectures are also recorded and he doesn't keep track of attendance. Haoren's office hours were also really helpful because he would show how to solve confusing problems from the homework and practice midterm--I found these more helpful than the lectures. The class was well organized and I felt that the tests were very similar to the practice tests. I think that I did so poorly, not only because of the teaching style, but also because of a mix of the TA strike, being overloaded by my other STEM classes, having the midterms returned 2 days before the final, and being new to UCLA. Still, I think I would have been able to get higher grades with less effort with a different professor. I would recommend trying to take the class with a professor who has more experience teaching/is better at explaining things. I know a lot of people are struggling in his 31AL class right now as well. If you do take this class, I recommend going to office hours and making sure that you understand everything in the practice midterm.
Also here is how it was graded:
15% Homework-graded on correctness, 2 lowest homework scores dropped
There are 2 midterms and a final
There are 2 Test Grading Schemes--they will chose whichever is higher
A: 20% each midterm, 45% final
B: Highest of the two midterms for 30%, Final 55%

Xiong is a terribly unfair professor who does not teach well enough and has incredibly hard tests. In lecture he mostly goes over proofs and very basic examples. The material itself is already pretty difficult and Xiong makes it even harder. One of the very few good things about his lectures are that they are recorded and his notes are posted. The workload honestly isn't bad but they do not compare to the tests which are exponentially harder and often times contain material that was barely ever mentioned. The only thing that got me through this class was my TA. DO NOT take this class with Xiong. Try to get another professor if you can.

Would not recommend taking this class with Xiong, especially if you do not have any background with Calc 2. His lectures are unengaging and he explained concepts in an overly complicated way. He is not helpful at all, so expect to self-study majority of the material. The workload was manageable as he assigns about 10 questions from the textbook about every other week, however these problems are all graded on accuracy and are worth 15% of your grade. The midterms were difficult given that we only had an hour to complete them, but I would say they were somewhat similar to the practice tests he gave us. The final was just absurd and the questions did not reflect anything we had done in the class. He curved the class, but this class was one of the worst classes I've taken at UCLA. If you want to succeed, attend TA Karthik's sections and watch Organic Chemistry Tutor's videos.

As someone who has usually enjoyed math before taking 31b with Xiong, I never wanna experience an environment like this ever again. The practice midterms and finals were completely irrelevant to the actual exams themselves. Lectures became a joke as it was almost impossible to understand a monotonic voice and heavy accent. The concepts themselves being taught in class were not understandable and complete different to the homework assigned. If you want a.real math professor for 31b just stick with ochem tutor and khan academy. Only reason I passed fr was cause of these goats. On all of westwood and odh don’t take this class with xiong.

This class may have been the most dreadful experience I have had at UCLA so far. As a person who usually understands and loves math, this course completely changed my feelings. His lectures are super boring, very unengaging, and you walk out not knowing a single thing that was said. His homework problems are related to the content taught in lecture (at least what I could understand) and it would be around less than 10 questions due every week. He has 2 midterms and 1 final (all in-person) and they are extremely complicated and questions that deviated a lot from the practices exams and homework's. EXAMS ARE VERY DIFFICULT AND YOU WILL NOT FEEL PREPARED FOR THEM AT ALL. Organic Chem Tutor on YouTube was what saved my grade, you basically have to teach the course yourself. The class average for the final was 64%... . I would not recommend taking this professor at all.