NEVER NEVER take his class in person! Otherwise, your life will be ruined and this very first proof-based math course will become your nightmare throughout the quarter.
ALL components in his class prevent you to genuinely from learning some math and gaining a good grade. You cannot understand his awkward accent at all since he speaks with mumbling and at least half of the words cannot be correctly pronounced. He just rushes through the course content so fast as if we have learned the course prior to his "reviewing style" teaching. When you find yourself lost in the class, you will feel so distressed and frustrated. Also, it is so difficult to understand his chaotic and obscure handwriting on board.
The grading schemes are one of the toughest I've ever seen: 60% for final, 25% for the mere midterm, and 15% for HW. Oh, if you bomb your midterm, then your final weighs 85% of your entire grade! :) Great huh?
No lecture recordings in this course. Only provide course notes which are also hard to read. Only around 20%-30% can gain an A or A-, and this course is totally curved (you need to beat others). This course is thus suitable for those who have learned it before and would like to retake it.
Last but not least, save your life and stay away from this course! (you really have many choices with different instructors tbh)

Yes, he has an accent. No, it does not hinder your ability to learn the material. However, I found my overall experience in Math 115A with Prof. Liu, frustrating to say the least. He's not really good at teaching the material (understatement) and communicating his ideas across. Even though it's supposed to be an intro to proof-based courses, he never really went over the basics of proofs. He assumed proofs would to come to us naturally, over time... which for me was like towards the end of the course ahaha. So if you can take Math 115A with a different professor, I would definitely recommend it, especially if you're a math major, since I feel as if Prof. Liu doesn't really prepare you for more abstract material. Don't get me wrong, he's not the worst, but yeah, I definitely spent the whole quarter self-learning the material--even the TA was pretty bad at explaining the material.

In terms of midterms and the final, the first midterm, the medium if I recall correctly, was 8.5/20, the second 12.5/20 and I don't know the scores for the final since Prof. Liu never posts the scores on myUCLA, only the final grade for the class. The first midterm I think was a bit difficult since it was more proof-based but the second midterm was a lot more manageable and computational. The midterms had 4 questions, 5 points each and the final had 10 questions, which were mostly computational. Trust me, you want the questions to be computational since those are the same topics covered in Math 33A. So if you did well in Math 33A, you'll do well in Prof. Liu's Math 115A course. ;)

However, out of the other 4 professors also teaching Math 115A, Prof. Liu had the most students drop out of his class so while it definitely is manageable to get an A, I would be very careful... He's definitely fair and wants students to do well, but everything else about him: his inept "style" of teaching, his unfriendliness in office hours and when you ask him questions (politely mind you), etc. sort of make him lean towards the "not-so-great professors" category.

girl zon't zo it

Terrible professor. Can't hear ANYTHING he says because his Chinese accent is so thick. Test's weren't that bad, but I literally had to go take the test instead of going to the hospital for tonsillitis (I couldn't breathe easily and couldn't swallow my own spit). I emailed him in the morning of the midterm and he said I couldn't skip, so I had to go to my midterm then walk directly to the ER. TA's were helpful asf, but super hard to take a class when you cant understand the professors speech, whos a hardass to begin with.

I have to say Professor Liu is the best professor I've ever seen in Math Department. I took the Math 115A with Prof. Liu last quarter and got an A+. His lecture is very clear and follows the textbook pretty well.

His exam is actually very easy because his first midterm involves proofs in only 2 out of 4 questions, and second midterm only half out of 4, and final only 3 out of 12. I got 20/20 in both the midterms, and the final grade is not given to us.

He is always very approachable and nice to talk to. He always helped me a lot when I asked him questions after classes.

His lecture basically talks about everything in the textbook, and he only added his own topics one or two times in the quarter. His exams covers from subspace to inner product space. He rushed in the week 10 to talk about a lot of topics on inner product space. But don't worry, the final doesn't cover those stuffs. Also in his class you don't really have to care about how you derived or proved the theorems, just memorize them and learn to use them is good enough.

I also have to thank my great TA Feng for his help. Graduated from the best university of China in the field of Math and Science,he is really really good at linear algebra that he can solve any of your questions in 1 minute. His office hour helped me a lot every time.

Dr. Liu is an excellent teacher for 115A. His teaching style does take a few lectures to get used to. He sometimes jumps from board to board, and often tries to squeeze in added details into very small spaces. However, once you get used to his notation and adjust to his style, you will be fine. As the first math upper div. you'll probably take, I believe Dr. Liu does a great job preparing you for the expectations of proof-based math. Dr. Liu does a great job with homework assignments. At the beginning of the quarter, he gives you a list of all the assignments for the class. Also, for our class, he assigned homework on Friday which covered everything we learned up until that day and was due the next Thursday. This was great because you could essentially finish the homework assignment over the weekend or at least start the assignment and ask questions during discussion or during office hours. I found Dr. Liu's exams very fair and straight forward. MOST OF THE QUESTIONS ON OUR EXAMS WERE COMPUTATIONAL. Which is a giant relief since proofs are definitely the trickiest part of 115A. However, this does not mean that the questions were similar to those of 33A, many of the problems are extended over different bases which makes things different. Still, I think most people will find computational problems easier than proofs. For our first midterm we had 1 proof, for our second midterm we only had to prove through computation, and for our final we had 3 proofs. My only problem was that Dr. Liu does not post your scores on MyUCLA, so it can be difficult to judge your standing to everyone else in the class. Still, I highly recommend Dr. Liu for 115A