posted by Mike .
The demand function for the Luminar desk lamp is given by the following function where x is the quantity demanded in thousands and p is the unit price in dollars.
p = f(x) = -0.1x2 - 0.3x + 39
(a) Find f '(x).
f '(x) =
(b) What is the rate of change of the unit price when the quantity demanded is 3000 units (x = 3)?
$ per 1000 lamps
What is the unit price at that level of demand?