Marginal Revenue

[racuna]

Suppose that the cost, in dollars, for a company to produce x pairs of a new line of shoes is
C(x)=2700+5x+0.03x^2+0.0002x^3

It asked me to find the marginal cost function, which is the derivative. I got
C'(x)=5+0.06x+0.0006x^2

Then it asked me to find C'(100) so I plugged it into C' and got the answer that it costs $17 to produce one pair of shoes.

Now, I have to find the cost of producing the 101st pair of shoes. I know that this is called marginal revenue, but I don't understand exactly how to do this part.
HELP!

 

[pka]

You wrote “it costs $17 to produce one pair of shoes”.
Actually that $17 is the marginal cost not the cost!
It tells us that in effect it cost about $17 to produce one more unit.
Thus C(101) is approximately C(100)+$17!