Answer:
1). ![P'(t) = (-9025t).e^{-0.05(53+0.95t^2)}](https://tex.z-dn.net/?f=P%27%28t%29%20%3D%20%28-9025t%29.e%5E%7B-0.05%2853%2B0.95t%5E2%29%7D)
2). (-435.36) dollars per week
Step-by-step explanation:
Weekly price decay of the product is represented by the function,
P(x) = ![95000.e^{-0.05x}](https://tex.z-dn.net/?f=95000.e%5E%7B-0.05x%7D)
And the price of the product changes over the period of 't' weeks is represented by,
x(t) = ![53+0.95t^2](https://tex.z-dn.net/?f=53%2B0.95t%5E2)
Function representing the rate of change in the profit with respect to the time will be represented by,
1). P'(t) = ![\frac{dP}{dx}.\frac{dx}{dt}](https://tex.z-dn.net/?f=%5Cfrac%7BdP%7D%7Bdx%7D.%5Cfrac%7Bdx%7D%7Bdt%7D)
Since, P(x) = ![95000.e^{-0.05x}](https://tex.z-dn.net/?f=95000.e%5E%7B-0.05x%7D)
P'(x) = ![95000\times (-0.05).e^{-0.05x}](https://tex.z-dn.net/?f=95000%5Ctimes%20%28-0.05%29.e%5E%7B-0.05x%7D)
= ![(-4750).e^{-0.05x}](https://tex.z-dn.net/?f=%28-4750%29.e%5E%7B-0.05x%7D)
Since, x(t) = 53 + 0.95t²
x'(t) = 1.9t
![\frac{dP}{dx}.\frac{dx}{dt}=(-4750).e^{-0.05x}\times (1.9t)](https://tex.z-dn.net/?f=%5Cfrac%7BdP%7D%7Bdx%7D.%5Cfrac%7Bdx%7D%7Bdt%7D%3D%28-4750%29.e%5E%7B-0.05x%7D%5Ctimes%20%281.9t%29)
By substituting x = 53 + 0.95t²
![\frac{dP}{dx}.\frac{dx}{dt}=(-4750).e^{-0.05(53+0.95t^2)}\times (1.9t)](https://tex.z-dn.net/?f=%5Cfrac%7BdP%7D%7Bdx%7D.%5Cfrac%7Bdx%7D%7Bdt%7D%3D%28-4750%29.e%5E%7B-0.05%2853%2B0.95t%5E2%29%7D%5Ctimes%20%281.9t%29)
P'(t) = ![(-9025t).e^{-0.05(53+0.95t^2)}](https://tex.z-dn.net/?f=%28-9025t%29.e%5E%7B-0.05%2853%2B0.95t%5E2%29%7D)
2). For t = 7 weeks,
P'(7) = ![(-9025\times 7).e^{-0.05(53+0.95(7)^2)}](https://tex.z-dn.net/?f=%28-9025%5Ctimes%207%29.e%5E%7B-0.05%2853%2B0.95%287%29%5E2%29%7D)
= ![(-63175).e^{-4.9775}](https://tex.z-dn.net/?f=%28-63175%29.e%5E%7B-4.9775%7D)
= (-63175)(0.006891)
= (-435.356) dollars per week
≈ (-435.36) dollars per week