Maths in Computer Science. What I wish I knew before starting university

I did an undergrad CS degree after ten years of working as a professional software developer, and then went on to do OMSCS. My classes for probability and matrixes assumed no particular knowledge of them so I didn't regret not learning anything about them before. Learning proofs from scratch for discrete math was very difficult though.

I had to pick up the notation, the logical patterns, the prose style, as well as the new model of reasoning all at the same time. If I were doing it again I would definitely get at least very basic familiarity with how proofs work before starting.

Also just algebra and basic math skills. I was having to go back and relearn like middle school math, I didn't have confidence with basic things like multiply and divide fractions, exponents, logarithms, etc.

I was trying to learn trig on the side to keep up with calculus and it was a disaster, I failed calc 1 the first time. Given the constraints I had with work I'm not sure how I could have prepared better, it's just too big of a gap to easily fill on nights and weekends in a few months. But yeah learn algebra and trig before you do a CS degree.

I was a math major before switching to cs. I’d say algebra/algebra 2/trig are the ones you need to be most skilled at the start.

Linear Algebra was quite possible to learn while in college as it wasn’t needed in the first few cs classes (useful for ai/ml/graphics)

After that my favorites were game theory and discrete math. They are quite practical in a way that fills out the way you can reason about the world. Again, definitely not needed before you start school.

I’m still waiting for calculus/ to be useful day to day, but then again I’m not doing engineering/physics simulation software where it is essential.