Question

Why am I getting this wrong? Exponential functions derivatives

Answer 1

A companys total cost in millions of dollars is given by C(t)=130-40e^-t where t is the time in years. Find each of the following.
Marginal cost of C'(t)
C'(0)
C'(4)
limC(t) t-->infinity and limC'(t) t--->infinity

Answer 2

So I got the derivative, 40e^-t
C'(0) is 40
C'(0) is just wrong

Answer 3

Round to the nearest thousand as needed

Answer 4

And I know C'(0) is 40 because it marked it correct. I already tried 40/e^4 which is 0.733

Answer 5

And it marked 0.733 wrong