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Math Help - Pert and Ab^t form

  1. #1
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    Question 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
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  2. #2
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    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
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  3. #3
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    Question 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?
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  4. #4
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    Quote Originally Posted by mathcalculushelp View Post
    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)])
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