Question

For the cost function, find the marginal cost at the given production level x.
C(x) = 15,000 + 90x + 1,000/x; x = 100

Answer 1

c(100) = 24010

Answer 2

Thats what I did but thats not the right answer. You don't just plug it in. You're supposed to change it using derivatives but thats where I get confused on.

Answer 3

C'(x) = 90 - 2000/x^2

Answer 4

is this one correct

Answer 5

actually, it's not
c'(x) = 90-1000/x^2

Answer 6

Yeah 89.9 was the right answer. Thank you!