# Marginal Revenue

• Feb 2nd 2008, 07:48 PM
XIII13Thirteen
Marginal Revenue
I need to find the marginal profit as tied into this equation

R=2x(900+32x-x^2)

with Marginal Revenue = $\frac{dP}{dx}$

a.) Additional revenue for x=14 to x=15

b.) Marginal revenue when X=14

c.) Compare b and a

The problem I'm having is that my marginal revenue looks nothing like my additional revenue hahaha

Marginal revenue is supposed to be gotten from the derivative of the equation that I wrote out as $2(32*2x)$. Part of this is from me dropping the 900 from the inside the () because it didn't have a x factor. Am I correct in doing this? This is supposed to create a "per unit" sort of equation. Am I doing something wrong? Thanks in advance
• Feb 5th 2008, 03:25 PM
chris_uk
The differentiated answer is =2(900+32x-x^2)+2x(32-2x)
Giving you an answer of -6x^2+128x+1800

as you have forgotton to use the product rule for differentiating two things multiplied together

as a quick check you can ensure that the highest power is one less than it was in the initial equation as this will be true if you have differentiated it correctly