Question

Lily is selling cups of lemonade for $1.75 each. The graph represents this scenario.

Choose the correct domain of the function in interval notation.

Answer 1

I don’t have the graph you mention — could you upload it or describe the x-values shown? That will let me give the exact interval.

A few notes so you can pick the right answer once you look at the graph:
- If the graph shows a continuous line starting at 0 and extending to the right with no upper bound, the domain is [0, ∞).
- If the graph shows a continuous segment from x = 0 to x = a (some finite a), the domain is [0, a].
- If the graph shows only discrete points at whole-number counts of cups (0, 1, 2, …), the domain is the set of nonnegative integers {0,1,2,…} — that is not an interval, so it cannot be written in interval notation.
- If the graph shows discrete whole-number points from 0 up to a maximum n, the domain is {0,1,2,…,n} (again not interval notation), but as an interval of x-values you would write [0, n] only if the graph includes every real x between 0 and n (continuous).

Tell me what the graph shows (continuous vs. dots, and the left/right endpoints) and I’ll give the exact domain in interval notation.