Why is the collection of finite unions of all sets of the form [a,b],[a,b),(a,b],(a,b) in the interval [0,1] not a sigma-algebra?
Clearly, it's an algebra, since
[0,1] is a finite union of disjoint subintervals,
the complement of a finite union is...
Hi! I've got a question about implicit functions.
I have to solve a system f(x,y,z)=0 in the neighbourhood of (1,1,1). I have a problem computing the derivative of an implicit function (x,y)=g(z), whose existence is given by the implicit function theorem when applied to the given function...