Direct variation and slope intercept form
(Ocoee, Florida, US)
What are some examples of slope intercept form representing direct variation?
Answered by Karin on Algebra-Class.com
Thank you for contributing to Algebra-class.com. Direct variation is when two variable quantities have a constant ratio. The formula for direct variation is:
y = kx where k is the constant of variation.
You asked for an example in slope intercept form. As you can see, direct variation is set up in slope intercept form.
y = kx is very similar to y = mx. With direct variation, the y-intercept is 0, so you won't have the "+b" portion of slope intercept form. The constant of variation (k) is very similar to the slope in slope intercept form.
Some examples of equations that represent direct variation are:
y = 5x
y = 1/2x
y = .3x
As you can see, these are all set up in slope intercept form (with a y-intercept of 0).
These equations are called "direct variation" because y varies directly with x. If x increases, then y increases as well. If x decreases, then y decreases.
I hope this helps.