How many elements has P (A), if A = Φ?
If A is a set with m elements
n (A) = m then n [P (A)] = 2m
If A = Φ we get n (A) = 0
n [P(A)] = 20 = 1
Therefore, P (A) has one element.
If A = {x : x ϵ R, x < 5} and B = {x : x ϵ R, x > 4}, find A ∩ B.
Prove that A – B = A ∩ B.’
Find the symmetric difference A Δ B, when A = {1, 2, 3} and B = {3, 4, 5}.
Prove that A ∩ (A ⋃ B)’ = ϕ
If A = {3, {2}}, find P(A).