In: Advanced Math
Recall that in class we defined, for any set A, P(A) := {B : B ⊆ A}, which we called the power set of A.
a) (10) Show that, if a set A has n elements (where n ∈ {0, 1, 2, 3, 4, . . .}), P(A) has exactly 2 n elements.
b) (10) Use #4(any infinite set S has a countably infinite subset) to show that, if A is an infinite set, P(A) is uncountable.