EXPLANATION
Given the exponential function:
45(1.085)^t
We have that 45=a is the initial value and 1.085 is the growth rate,
1.085 - 1 = 0.085* 100 = 8.5 % (This is the growth rate)
Let's compute the function with two values of t, as for instance, t=0 and t=1:
[tex]f(0)=45(1.085)^0=45\cdot1=45\longrightarrow\text{ (0,45)}[/tex][tex]f(1)=45\cdot(1.085)^1=48.825\text{ }\longrightarrow\text{(1,48.825)}[/tex]Now, the function in the form y = ae^kt will be as follows:
[tex]y=45\cdot e^{kt}[/tex]Substituting t by 1:
[tex]y(1)=45\cdot e^k=48.825[/tex]Dividing both sides by 45:
[tex]e^k=\frac{48.825}{45}=1.085[/tex]Applying ln to both sides:
[tex]k=\ln 1.085[/tex]Computing the argument:
[tex]k=0.0816[/tex]The expression will be as follows:
[tex](a)---\longrightarrow y=45e^{0.0816t}[/tex]As this is a growing function, the rates are positive.
The annual growth rate is 8.5% and It's was calculated above.
Now, we need to compute the continuous rate because It's given by the value of k:
k = 0.0816 --> Multiplying by 100 --> 0.0816 * 100 = 8.16%
The continuous growth rate is 8.16%