im stuck on ii(i) find k3) A culture of bacteria is growing at a rate proportional to the number,
, of bacteria present, so that:
where is the time elapsed in hours and is a constant.
Initially, the culture contains 3000 bacteria,
and after three hours, it contains 9000 bacteria.
(i) Find k.
Thereafter (that is, for t > 3), the culture is washed with a solution
which is harmful to the bacteria, and the bacteria are killed off
at a constant rate of 4500 per hour.
(ii) Find the number of bacteria in the culture for any time t > 3.
(iii) After how much washing time (hours/minutes) do the bacteria die out?
I got
Which gives: ...............................
ii) find the population after 3 hrs (i.e. t>3)
Ok. so first I thought it was
then i thought it this:
Now im thinking
yeh so any tips...is it the last one?