Question

Derivatives application problem?

Answer 1

http://prntscr.com/2vg00j

Answer 2

take the derivative of, pf its just the product rule

Answer 3

or in this case, pq i spose .... whatever you want to name them

Answer 4

(pf) = ____ + _____

Answer 5

forgot a ' :/

Answer 6

Okay so..
\[\LARGE R(p)= pf'(p)+f(p)p'\]

Answer 7

yep, and in this case, p' = dp/dp=1

Answer 8

So now plug in the given values?

Answer 9

of course ....

Answer 10

and its R'(p) but thats just semantics :)

Answer 11

R'(p) = pf' + f

R'(18) = 18(-310) + 9000

Answer 12

I knew I was missing something, thanks amistre :D

Answer 13

yep ;)