Answer:
a) 0 ≤ d ≤ 21 . . domain; 0 ≤ B ≤ 400 . . range
c) B(12) = 0
d) 4th segment
Step-by-step explanation:
(a) The domain of the function B(d) is from d = 0 to the number of days the account was open:
0 ≤ d ≤ 21 . . . . domain
The range is the set of values the bank balance might have. We know the minimum is 0 and the maximum is 400:
0 ≤ B ≤ 400 . . . . range
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(b) (missing question content)
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(c) The balance on day 12 is B(12). We're told it is zero, so...
B(12) = 0
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(d) The 4th segment of the graph is at B(d) = 0.
In this context, it is reasonable to assume the vertical scale starts at 0 at the horizontal axis. We are told that (12, 0) is a point on the graph. It is consistent with this assumption that slightly more than halfway through the graphed domain, the graph meets the horizontal axis. The graph stays at the horizontal axis for "segment 4."