Answer:
A ∪ B = (-∞, 3) ∪ [6, ∞)
A ∩ B = ∅
Step-by-step explanation:
The union of the two sets is the set of values in one or the other or both.
A ∪ B = (-∞, 3) ∪ [6, ∞)
The intersection of the two sets is the set of values in both. Here, the sets do not overlap, so the intersection is the empty set.
A ∩ B = ∅
_____
Additional comment
Interval notation uses an ordered pair to specify the range of values in the interval of interest. A round bracket (parenthesis) is used when the end value is not included in the interval. A square bracket [ ] is used when the end value is in the interval. Infinity is always accompanied by a round bracket, The first member of the pair is the left end of the interval on the number line.
For example, the range -∞ < x < 3 is noted by (-∞, 3).
