(1) There is a certain relationship between polar coordinates and advanced mathematics, but in many provinces, high schools don't learn polar coordinates, so teachers in universities will explain them appropriately, and there is not much about polar coordinates in universities (at least we didn't pass the exam, so I don't know if you studied mathematics in universities).

(2) Inequality is mainly to exercise your thinking, which has something to do with the university, because you must still use inequality in advanced mathematics, but it won't be too deep.

(3) If you only think about college, there is actually a lot of time for you to study by yourself in college. But as far as mathematics is concerned, taking these elective courses is to exercise thinking and cultivate logical ability.

I hope my answer will help you. Work hard.