Suppose the cost C(q) (in dollars) of producing a quantity q of a product equals

Question

C(q) = 500 + 2q +1/5q2.

The marginal cost MC(q) equals the instantaneous rate of change of the total cost.
Find the marginal cost when a quantity of 10 items are being produced.

Answer 1

assume you mean:
C(q) = 500 + 2q +(1/5)q^2

dC/dq = 2 + (1/5) 2 q
= 2 + (2/5) q

when q = 10 this is
2+4
= 6 = cost of 11th item