Answer:
Change in annual cost is 1.63 (decreasing).
Instantaneous rate of change is 1.65 (decreasing).
Step-by-step explanation:
Given that,
The annual change in cost is given by,
Calculate the value of cost at Q = 347 and Q =348 by substituting the value in cost function.
Calculating value of C at Q=347,
Calculating value of C at Q=348,
Substituting the value,
Negative sign indicate that there is decrease in annual cost when Q is increased from 347 to 348
Therefore, change is annual cost is 1.63 (decreasing).
Instantaneous rate of change is given by the formula,
Rewriting,
Now calculate \dfrac{C\left(Q+h\right) by substituting the value Q+h in cost function,
Therefore,
By using distributive law,
Cancelling out common factors,
Now, LCD of and is . So multiplying first term by and second term by
Therefore,
Simplifying,
Factoring out h from numerator,
Cancelling out h,
Calculating the limit by plugging value h = 0,
Given that Q=347,
Negative sign indicate that there is decrease in instantaneous rate when Q is 347
Therefore, instantaneous rate of change at Q=347 is 1.65 (decreasing).