ϕ ⊂ {a, b, c}
True
False
What is (A ∪ A′)?
ϕ
U
A
A′
Match the equal sets.
{x : x2 – 4 = 0, x ∈ Z}
{x : x is a letter of the word PICNIC}
{x : x = n + 3, n ∈ N, n < 5}
{x : x is a month having 30 days}
{x : x+ 2 = 0, x ∈ Z}
{–2, 2}
{P, I, C, N}
{4, 5, 6, 7}
{April, June, September, November}
{–2}
equal
disjoint
empty