exercise 2.
1)prove whether or not the set S is countable.
a) S = { irrational }
b) S = { terminating decimals }
c) S = [0, .001)
d) S = Q X Q
e) S = R X Z
2) prove that the intersection of two countable sets is countable.
3) prove whether or not the intersection and union of two uncountable sets must be uncountable.
4) prove that the cartesian product of two countable sets AX B = { (a,b): aεA and bεB) }
5) prove that a countable union of countable sets is countable.
reply soon.