Math  Derivative of a polynomial function
posted by Anonymous .
The population, p in thousands of bacteria colony can be modelled by the function p(t)=200+20tt^2, where t is the time, in hours, t is greater than or equal to zero.
a) Determine the growth rate of the bacteria population at each of the following times.
i>3h
ii>8h
Ans: find the 1st derivative which is 202t, substitute the times given and it yield a negative number and that in thousands is the answer.
b)What are the implications of the growth rates in part a)
Ans: since the answer are negative they suggest that the population of the bacteria is decreasing.
c)When does the bacteria population stop growing? What is the population at this time.
Ans: set the original equation to zero it will give a time in hours and substitute that time into the first derivative.

It seems to me that your question contains the answers, or at least the means of calculating them. Why just you don't just follow those directions?

i just wanted to know if it is the correct way of going about with them, i forgot to put the (check) in the title.