Question

The cost (in dollars) of producing x units of a certain commodity is
C(x)=2000+18x+0.3x2.


(a) Find the average rate of change of C with respect to x when the production level is changed
(i) from x=100 to x=105.

Average rate of change =

(ii) from x=100 to x=101.

Average rate of change =
(b) Find the instantaneous rate of change of C with respect to x when x=100. (This is called the marginal cost.)

Instantaneous rate of change =

Answer 1

Is it like this?
\[\Large C(x)=2000+18x+0.3x^2.\]

Answer 2

yes

Answer 3

i got the first 2 now i just need the last one