Question

If A and B are any two sets, prove that
(i) A⊂(A∪B)

Answer 1

Answer:

A⊂B⇔A∪B=B

⇒(A∪B)

′

=B

′

USING DEMORGAN'S LAW

⇒A

′

∩B

′

=B

′

⇔B

′

⊂A

′

Answer 2

Answer:

A={1,2,3} and B={2,3,4,5}

AUB={1,2,3,4,5}

so A is the Subset of AUB