Question

Identify the domain of the function

A: (2, 8)
B: [2, 8]
C: (−5, 9)
D: [−5, 9]

Answer 1

B: [2, 8]

Explanation:

Domains is the set of all inputs(x values)

Square brackets "[ ]" are used when the boundary is included

Round brackets "( )" are used when the boundaries are excluded

The closed dots indicate both the boundaries are included,

Therefore the domain is:

[2, 8]

Answer 2

B. [2, 8].

Explanation:

The domain refers to the set which values belongs to the independent variable
`x` (horixontal axis).

So, to find the domain with a graph, we need to look for the beginning and the end of the function. Then, we look for x-values at those points.

The beginning point is (2,9) and the ending point is (8,3).

So, the domain is from x=2 to x=8.

Therefore, the right answer is B. [2, 8].

In this case, both points have a filled circle, which means the intervals must be closed. In other words, 2 and 8 are part of the domain, and the way to express that is with ][ signs.