Question

for the given function, use your intuition or additional research, if necessary, to complete parts (a) through (c).
(time, number of bacteria), where time is measured in hours of a day
a. describe an appropriate domain and range for the function.
b. make a rough sketch of a graph of the function.
c. briefly discuss the validity of the graph as a model of the true function.
choose the appropriate range for the function.
a. the range is all bacteria during a given day, or 5 cells to 120 cells.
b. the range is all bacteria during a given day, or 10 billion cells to 25 billion cells.
c. the range is all hours in a day, or 1 to 24 hours.
d. the range is all hours in a day, or 25 to 36 hours.

Explanation:

The function is (time, number of bacteria), so the range should be the set of possible number of bacteria values. Option C and D refer to hours (which is the domain, not range), so they are incorrect. Option A has too low a number of bacteria (5 - 120 cells is unrealistic for a day's growth), while Option B (10 billion to 25 billion cells) is a more reasonable range for bacterial growth over a day.

Answer:

B. The range is all bacteria during a given day, or 10 billion cells to 25 billion cells.