You might think this class is hard, but it's not that bad. The problem is that the professor's teaching is really torturous. His thick accent and postmodern deconstructionist-style blackboard writing make it impossible for you to understand what he's saying and teaching. As a result, I had to study this course all by myself throughout the quarter.

DO NOT TAKE THIS CLASS. This class is an absolute joke.
Koffi uses slides from other previous professors (only hiding the other instructor's name while using the slides in class). The slides can be found here: https://sites.math.rutgers.edu/~sc2518/170S. This is almost certainly ACADEMIC PLAGIARISM...To a worse extent, he never explains clearly what is he doing in the class, and not exaggeratingly, half of his math computations are purely wrong (once he wrote 60/4=12 and left that on the board without noticing).
He is an incompetent teacher who only knows reading off the slides (not even his own slides) and it is likely that he doesn't even know about the course materials himself. Lecture pace was also awfully designed--we lagged an entire chapter at the end of the quarter compared to the other class.
Some comments say that he is nice as a person--it's not the way I perceive--my final exam was graded by Professor himself and two of the questions were graded wrongly. I respectfully tried to ask for regrade but he only responded me with Gen-AI texts (even not deleting ReGex expressions) and rejecting my points without taking a closer look.
If you have no choice but to take this class with him, get prepared for self-learning and unreasonable gradings.