An example of direct variation is buying gas. When you pump the gas, the total price varies directly as a function of the number of gallons of gas you pump. The constant of variation is the price per gallon. So, if gas costs $2.50 per gallon, the equation is y = $2.50x where x is the number of gallons pumped and y is the total price. If you pump 10 gallons of gas, the price is $25.00.
Note that direct variation always has a y-intercept of zero. The graph of the direct variation
above looks likes this:
All Math Words Encyclopedia is a service of
Life is a Story Problem.org.
Copyright © 2005-2011 Life is a Story Problem.org. All rights reserved.
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License