# Thread: More exponentials and logs!

1. ## More exponentials and logs!

Its me again

The question I'm stuck on now is (this is gonna be diificult to type/understand)

Population of orchids is shown by (p is population and t is years from start)

p = 2800ae^(0.2t)/
1+ae(0.2t)

Given that population is 300 when study started (this means that time=0, right?)

a) prove that a=0.12, which I have done

b) use this to predict no of years before the population reaches 1850

does this mean that you make p=1850 and solve for t?

so,

1850 = 336e^(0.2t)/
1+0.12e^(0.2t)

I'm not too sure what to do from here?

c) show that,

p= 336/
0.12+e^(0.2t)

d) hence show that population cannot exceed 2800

I know its alot to ask for but I would be very grateful to anyone who would be kind enough to help me

2. ## Re: More exponentials and logs!

Hint: For (b) you are setting p=1850. When you have 1+0.12e^(0.2t), trying using natural log.