The decay of a certain substance is modeled by the function N(t)=100(3+e^(-t/3), where the number of particles is represented by N in a time of t hours.

Question

a) what is the initial number of particles?
- I set t as 0 and got an answer of 400 particles initially

b) determine the rate of change in the number of particles at time t
- Am I to find the derivative of the function? after that what would i do?

c) how fast is the number of particles changing when t=3 hours.
- would I sub in t=3 into the equation from part b?

Answer 1

a) correct

b) since you want the rate at a time of t, your derivative is your answer

c) you would sub t = 3 into the derivative, the rate of change, that you found in b)

Answer 2

thanks!