How does elasticity differ from the slope of the demand curv

How does elasticity differ from the slope of the demand curve?

Solution

Slope of the demand curve is change in demand divided by the change in price of a commodity. By how much price of a commodity needs to change for customers to demand one more unit of it.

Slope of demand curve = p/q = 1/ q/p

Elasticity of demand = q/q / p/p

One basic difference between the two is also that the slope of demand curve is constant throughout whereas elasticity of demand is different at different sets of prices.