Given:
The cost of new equipment = $ 420,000.
The depreciation rate is 6 % annually.
The variable t represents the time.
Aim:
We need to find the exponential function f(t) that models the value of the equipment over time.
Step-by-step explanation:
The exponential function f(t) is decay function.
Consider the exponential decay function.
![f(t)=a(1-r)^t](https://img.qammunity.org/2023/formulas/mathematics/college/gtthwbzxs5whzywc32nhlcn3cadmvvpa8c.png)
where a is the initial value and r is the decay rate.
The initial value = the cost of new equipment, a = 420,000.
The decay rate = the depriciation rate, r =6% =0.06.
Substitute a =420000 and r = 0.06 in the decay exponential function.
![f(t)=420000(1-0.06)^t](https://img.qammunity.org/2023/formulas/mathematics/college/vxpku4kks81n0227phch38pi23wbbhjyet.png)
![f(t)=420000(0.94)^t](https://img.qammunity.org/2023/formulas/mathematics/college/87ia1x5ts46de1cxrfso98s4omtotjvlda.png)
Final answer:
The equation for an exponential function f(t) that models the value of the equipment over time is
![f(t)=420000(0.94)^t](https://img.qammunity.org/2023/formulas/mathematics/college/87ia1x5ts46de1cxrfso98s4omtotjvlda.png)