Summary of Section 5.5 from Text web site:
http://www.zweigmedia.com/ThirdEdSite/Calcsumm5.html Elasticity of Demand The
where the demand equation expresses demand, q, as a function of unit price, p. We say that the demand is To find the unit price that maximizes revenue, we express E as a function of p, set E = 1, and then solve for p. | Example
Suppose that the demand equation is q = 20,000 - 2p. Then
If p = 2,000, then E = 1/4, and demand is inelastic at this price. If p = 8,000, then E = 4, and demand is elastic at this price. If p = 5,000, then E = 1, and the demand has unit elasticity at this price. Top of Page |

Proposition:

Proof:

If

So d