I really loved 131A with Professor Wu! He is an amazing professor, during lecture he used many colored chalks and helped build intuition for the harder concepts. He also always provided midterm/final reviews and during office hours he was very approachable and helpful. Although the class is one of the hardest math courses, this class really helped me build strong foundations in proof writing and core concepts I still use. It was overall a very rewarding class, so if you have the option to take 131A with Wu, I highly recommend. You will learn a lot and are in good hands :)

A lot of the difficulty in this class is centered around Analysis just being a really tough topic. Homework was tough, and Professor Wu also did not record any lectures (or post his notes as he did his entire lecture on the chalkboard) so attending lecture in-person is a must to be successful. However, he posted lengthy PDF notes that served as both a textbook / lecture notes that were helpful, as exams were directly based on proofs done in these notes and homework. Exams were on the easier side, since they modeled the practice exams almost entirely. However, a practice exam was not provided for the final, which made it more difficult. Ultimately, I would recommend taking this class with Professor Wu given the exams, but it will still be a difficult class.