Originally Posted by
iwan1981 I need some help with understanding this question as well:
==================================== A – B = {x|x ∈ A ∧ x ∉ B}
A = {a, b, e, f}
B = {b, d, g, f, a}
Match the following to the correct answers.
A – B = ?
B – A = ?
Answers:
a. {a, b, f}
b. {a, b, e, f}
c. {d, g}
d. {e}
====================================
What I understand here is that x has elements in A and that those elements are not part of B.
No. x is not a set. It represents a element in A-B. So your statement should be corrected as, "A-B includes all the elements in A which are not in B".
So when we do A - B the correct answer is: c. {a, b, f}
This is incorrect as a,b and f are in B.
and B - A would be: c. {d, g}
Is this correct?
Correct
Thanks,