If A – B = A, then (A∩B) = ___.
{ }
A
A∪B
B
The difference of two sets is the set of elements which belong to 1st set but not the second set.
If A – B = A, then A and B are disjoint sets.
(A∩B) = { }
There are no elements common to A and B.
[(B′∪(B′−A))]′ =_____
If the point P(p, q) is equidistant from the points A(a+b, b-a) and B(a-b, a+b), then pq = ___