The cost function for the manufacture of mp3 players is $\displaystyle C(x) = 25000 + 20x + 0.001x^2$ Dollars.

a) How many mp3 players should be manufactures to minimize the cost?

b) What is the resulting average cost of an mp3 player?

Note: X= number of mp3 manufactures

====

I'm stumped. This question was given to me by my Finite Maths teacher under the topic of 'Application of Derivatives', and I don't seem to be making any progress. I'd appreciate it if you guys could help me out

thanks!

EDIT: Correction in the problem