The total weekly cost (in dollars) incurred by Lincoln Records in pressing x compact discs is given by the following function.

C(x) = 2000 + 2x - 0.0001x^2 (0≤x≤6000)

(a) What is the actual cost incurred in producing the 1071st and the 1891st disc? (Round your answers to the nearest cent.)
1071st disc=$

1891st disc=$

(b) What is the marginal cost when x = 1070 and 1890? (Round your answers to the nearest cent.)
1070=$

1890=$

2 answers

a) Plug in x = 1071, and x = 1891 into the equation C(x) to find the actual cost at these values.

b) The marginal cost is the cost of producing one more extra good, so the marginal cost when x = 1070 is

C(x=1071) - C(x=1070)

for 1890 it is

C(x=1891) - C(x=1890)
Im not sure if this is right.