Question

The cost of manufacturing x cases of fillfluff is C dollars (in thousands), where C(x) = 4 x + 4 sqrt(x) + 5

Monthly production at t weeks is expected to be x = 6400 + 90 t

Write an equation to express rate of change of cost with respect to time:
(dC)/(dt) =

Answer 1

\[\frac{dC}{dt}=\frac{dC}{dx}\frac{dx}{dt}\]

Answer 2

\[\frac{dx}{dt}=90\]
\[\frac{dC}{dx}=4+\frac{2}{\sqrt{x}}\]

Answer 3

thats the marginal cost

Answer 4

how can you find the rate of change?