# Math Help - Pert and Ab^t form

1. ## Pert and Ab^t form

Below gives values of an exponential function P.Give a formula P(t) in the form P(t)=Poa^t and also in the form P(t)=Poe^rt.If rounding is necessary round to 4 decimal places.

t | 0| 1 | 2
P(t)| 60 | 94.8 | 149.784

2. $P(t)=P_{0}a^t$, subs $t=0$, we get $P_{0}=60$. subs $t=1$, you'll get $a$.

for $P(t)=P_{0}e^{rt}$, subs $t=0$ and $t=1$ (or $t=2$) you'll get $P_{0}$ and $r$

3. ## finding r

For
P(t)=Poe^rt

am putting t=0
so Po=60

how do i get r?

once i get Po and r ..do i plug it in the formula?

4. Originally Posted by mathcalculushelp
For
P(t)=Poe^rt

am putting t=0
so Po=60

how do i get r?

once i get Po and r ..do i plug it in the formula?
You shouldn't use that point because for t=0: $e^{rt} = e^0 = 1$

Instead use the next point at t=1

$r = \frac{1}{t}(ln[P(t)]-ln[P(0)])$