Module 3 – Polynomial and Rational Functions

3.1 – Linear and Quadratic Functions

Introduction

A shoe retailer finds that she can sell (on average) 50 pairs per week of a certain style when the price is $50 per pair, but that for each $5 she raises the price she loses 4 sales. If this relation persists over a range of prices then a plot of number of sales vs. price would produce a straight line, and so we say there is a linear relationship between price and sales. But the store owner’s weekly revenue is obtained by multiplying the price she charges by the number of pairs she sells, and one goes down as the other goes up so the combined effect is not so obvious. One of the things you will learn in this section is how to analyse the above situation so that you can tell the retailer what price to charge in order to maximize her weekly revenue.

What to Do

1. Use the Study Notes and Discussion re Linear Functions to guide your review Section 2.3 of the text, and follow the instructions regarding Further Practice to confirm your understanding.
2. Use the Study Notes and Discussion re Quadratic Functions to guide your reading of Section 2.6 of the text, and follow the instructions regarding Further Practice in those notes as well.
3. When you feel that you have achieved the learning objectives for this section, move on to the next.