If you scale up x by a certain amount and y gets scaled up by the same amount, then it's direct variation. If you scale up x by some-- and you might want to try a couple different times-- and …

y=k*1/x is the only form of inverse variation, although it can look quite different when you apply some algebraic manipulation. For instance, y=k*1/x is the exact same thing as y=k/x, or xy=k.

So that's, these are the tell-tale signs for inverse variation. Now finally they talk about something called joint variation, and this one you won't necessarily see in introductory algebra course.

Sal models a context about lengths of strings and the frequency of their vibrations! with an inverse variation equation. Created by Sal Khan and Monterey Institute for Technology and Education.

This is inverse variation. And you see in either one of these, they're on different sides of the equal sign. So let's take this first relationship right now. Let's multiply both sides by n. And you get m, …

Given a few two-variable equations, find those that show direct or inverse variation.

Practice Up next for you: Recognize direct & inverse variation Get 3 of 4 questions to level up!

This video explains the concepts of direct and inverse variation with examples to help students understand their applications in real-life situations.

Direct Proportion Learn Intro to direct & inverse variation Direct variation word problem: filling gas

Learn about inverse variation in algebra through interactive exercises and videos on Khan Academy.