A) A reasonable domain to plot the growth function is; d = 9.02
B) The y-intercept of the function is; 9
C) The average rate of change of the function f(d) from d = 3 to d = 9 is; 0.4477
<h3>What is the domain of the function?</h3>
We are given the equation that shows the radius of the algae, f(d), in mm, after d days as; f(d) = 9(1.04)^(d)
A) We are told that the radius is approximately 12.81 mm. Thus;
9(1.04)^(d) = 12.81
(1.04)^(d) = 12.81/9
(1.04)^(d) = 1.4233
d * log 1.04 = log 1.4233
d = 0.1533/0.017
d = 9.02
B) The y-intercept is obtained when the domain is zero. Thus;
f(0) = 9(1.04)^(0)
f(0) = 9
C) Average rate of change is given by the formula;
f'(x) = [f(b) - f(a)]/(b - a)
from d = 3 to d = 9. Thus;
f'(x) = (f(9) - f(3))/(9 - 3)
f'(x) = (9(1.04)^(9) - 9(1.04)^(3))/6
f'(x) = 0.4477
Read more about Domain of function at; brainly.com/question/10197594
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