Math 142
Section 4.5 Examples
Example 1: The demand function for a particular brand of dog sweaters is x = −2p3 +22p+18000,
where x is the number of dog sweaters and p is the price per dog sweater.
a) Calculate elasticity of the demand function.
b) Is it elastic, inelastic, or unit elasticity at p = $20?
c) Is it elastic, inelastic, or unit elasticity at p = $5?
Math 142
Section 4.5 Examples
Example 2: The demand function for a particular commodity is given by x = 173, 280 − 40p2 . At
what price will revenue be maximized?
Example 3: When the price for a particular brand of shoes is $60, the elasticity E(60) = 2.5.
a) If the price is raised by $0.60, will the demand increase or decrease? By what percent will the
demand change?
b) If the price is lowered by $8, will the demand increase or decrease? By what percent will the
demand change?