Kenneth Rosen Edition 7 Exercise 2.2 Question 4 (Page No. 136)

Question

Let $A= \left \{ a,b,c,d,e \right \}$ and $B= \left \{ a,b,c,d,e,f,g,h \right \}$. Find

1. $A \cup B$
2. $A \cap B$
3. $A-B$
4. $B-A$

Answer 1

1. A U B = (This set contain element either in set A or in set B and repeated element comes only once )

Therefore A U B ={ a,b,c,d,e,f,g,h}

2. A ∩ B= (This set contain element set A and in set B (both) )

Therefore A ∩ B ={ a,b,c,d,e}

3. A -- B(Set difference)=  (This set contain element in set A and not in set B)

Therefore A --B ={ empty} or Φ because none of the element in set A which is not in B.

4. Same as that B--A = (f,g,h)