# Math Help - Price Elasticity of Demand

1. ## Price Elasticity of Demand

I know this is an economics subject, however I have learned it this term in University Intro Calculus. I have continually had trouble with it and have never gotten anything right. Here are two questions:

1. Demand: p=600-5x at x=30
2. Demand: p=5-0.03x at x=100

I need to find the price elasticity of each and determine whether or not it is elastic or inelastic.

Auger

2. Originally Posted by Auger
I know this is an economics subject, however I have learned it this term in University Intro Calculus. I have continually had trouble with it and have never gotten anything right. Here are two questions:

1. Demand: p=600-5x at x=30
2. Demand: p=5-0.03x at x=100

I need to find the price elasticity of each and determine whether or not it is elastic or inelastic.

Auger
Recall Price elasticity demand = % change in quantity demanded/ % change in price

in calculus it is = p/q* (change in Q/change in p)
Change in Q/change in p is the slope of demand curve

Given a linear Demand q= a-bp
Elasticity = -bp/q = -bp/(a-bp)
q= quantity demand, p=price

hope this helps