f(t) is an exponential function with
f(0) = 200 and f(3) = 2000.
a) Use the form f(t) = Pe^rt to find the equation of this exponential function.
b) In the form f(x) = Pa^x, a is the growth factor. find the growth factor.
c)What input value gives an output value of 5,000?
2 answers
mr.jagodnishvil
200 = Pe^0 = P
2000 = Pe^rt = 200e^3r
e^3r = 10
3r = ln 10
r = ln10/3 = 0.7675
f(x) = 200a^x = 200e^.7675x
a^x = e^.7675x
a = e^.7675 = 2.154
5000 = 2.154^x
ln 5000 = x ln 2.154
x = ln5000/ln2.154 = 11.1
2000 = Pe^rt = 200e^3r
e^3r = 10
3r = ln 10
r = ln10/3 = 0.7675
f(x) = 200a^x = 200e^.7675x
a^x = e^.7675x
a = e^.7675 = 2.154
5000 = 2.154^x
ln 5000 = x ln 2.154
x = ln5000/ln2.154 = 11.1