A biologist is studying the growth of a particular species of algae. She writes the following equation to show the radius of the algae, f(d), in mm, after d days:

f(d) = 9(1.04)d

Part A: When the biologist concluded her study, the radius of the algae was approximately 12.81 mm. What is a reasonable domain to plot the growth function?

Question

A biologist is studying the growth of a particular species of algae. She writes the following equation to show the radius of the algae, f(d), in mm, after d days:

f(d) = 9(1.04)d

Part A: When the biologist concluded her study, the radius of the algae was approximately 12.81 mm. What is a reasonable domain to plot the growth function?

Luigi0210 · Answer

The domain is associated with the x-values. You are given the radius of algae, f(d), as 12.81. So you can set it equal to the equation to get an x value for the maximum domain. With 0 being the lowest (since time starts at 0).

$$\large 12.81= 9(1.04)^d$$