Question

The total cost C(x) associated with the production x units of an item is given by C(x) = 0.005x³ – 0.02x² + 30x + 5000. Find the marginal cost when 3 units are produced, where by marginal cost we mean the instantaneous rate of change of total cost at any level of output.

Answer 1

Marginal cost = C'(x) = 0·015 x² – 0·04x + 30

At              x = 3, C'(3) = 30·015