A population of fruit flies starts with 6 flies. On Day 4, the population has grown to 94 flies. Write an exponential growth function to model the growth of the fly population.
We have.....
Pt = Pbt-1 where P is the original population .... Pt is the popoulation after "n" days ... b is the growth rate... and t is the number of days ...[ t = 1 is the first day.....so, we're looking for the population 3 days after. the first day = the end of the 4th day ]....and we have
94 = 6b(4 - 1) = 6b(3) divide both sides by 6
(94/6) = b3 take the cube root of both sides
b ≈ 2.5022
So, our function is : Pn = 6(2.5022)(t - 1)
We have.....
Pt = Pbt-1 where P is the original population .... Pt is the popoulation after "n" days ... b is the growth rate... and t is the number of days ...[ t = 1 is the first day.....so, we're looking for the population 3 days after. the first day = the end of the 4th day ]....and we have
94 = 6b(4 - 1) = 6b(3) divide both sides by 6
(94/6) = b3 take the cube root of both sides
b ≈ 2.5022
So, our function is : Pn = 6(2.5022)(t - 1)
Would it be reasonable for me to do it like this?
A population of fruit flies starts with 6 flies. On Day 4, the population has grown to 94 flies. Write an exponential growth function to model the growth of the fly population.
$$\\P=6e^{k(t-1)}\\\\
94=6e^{3k}\\\\
15.\dot6 = e^{3k} \\\\
ln(15.\bar6 )= ln(e^{3k}) \\\\
ln(15.\bar6 )= 3k \\\\
k=ln(15.\bar6 )/3 \\\\
k\approx 0.91718\\\\
so\\\\
P=6e^{0.91718(t-1)}\\\\$$
Is that ok?