Question

Using a number line, find both the intersection and the union of the following

intervals:
(-3,∞) and (4,∞)

Answer 1

The intersection of the two intervals = 4, 5, 6,.......∞ = (4, ∞)

The union of the two intervals = -3, -2, -1, 0, 1, 2, 3, 4, 5,.....,+∞ = (-3, ∞)

Explanation:

The given intervals are;

First interval = (-3, ∞)

Second interval = (4, ∞)

Using the number line, we therefore, the first interval includes, -3, -2, -1, 0, 1, 2, 3, 4, 5,.....,∞

The second interval includes 4, 5,.....,∞

Which gives the intersection as 4, 5, 6,.......∞

The union is the interval that combines the two sets of intervals which is given as follows;

The union of the two intervals = -3, -2, -1, 0, 1, 2, 3, 4, 5,.....,∞