The prerequisites for the course say that high school algebra and trigonometry are needed but this is very vague. What kind of topics should I know exactly?

Question

phi · Answer

There is no time limits.  Try watching the lectures and doing the exercises. If you run into trouble, that will tell you what you have to study (or review).

anonymous · Answer

Though Phi's response is very true and usable, it is kind of general so to add to it, here is a list of thing you should be expected to have in your toolbox:

Trig: 
Simple angles like $$\cos^{-1} (\frac{ Side }{Hypotenuse})$$
A basic knowledge of the workings of trigonomic functions, in specific the graphs of Sine and Cosine.

Algebra:
You should be able to easily and confidently solve basic inequalities, including 2 variable inequalities when 2 different functions are given. $$f(x,y)$$ & $$g(x,y)$$ you should be comfortable solving inequalities that do not include any numbers but instead focus entirely on variables and named constants.

Looking through some of the early problems should give you an idea of what you will need to specifically be able to do.