there's another part to the question. analysis really is the hardest module. the uni blackboard is really quite a mess of 100s pages just for this module, i just need any help to get me in the right direction thanks
the point is, det is a function from . you should already know that s(x,y) = x+y is continuous from , and that p(x,y) = xy is continuous from .
so det(a,b,c,d) = s(p(a,d),-p(b,c)), which is a composition of continuous maps, yes?