Friday, September 2, 2011

Direct and Inverse Variation

Direct and Inverse Variation are two very important concepts to know in Algebra 1, as well as future math classes. We'll start with Direct variation. In direct variation, an equation formula such as y=kx will be used. This means, that there is a constant number that can be multiplied by an X value to get a Y value. As X increases, so does Y. When you divide the increase in Y by the increase in X, you get your constant, or K. Take a look at the below picture:

As, for Inverse Variation, it's a little different. We use the equation y=k/x to solve. You can always divide the constant by the X value to get a Y value. When the X value increases, the Y value decreases. Take a look at this example:



  1. Thanks Alison, nicely done. I especially like how you worked out some examples, took pictures, and included them in your blog post. I think the visual really helps your reader better understand what you are talking about.

    You started by stating that Direct and Inverse Variation are two very important concepts in Algebra 1. I agree, of course :-), but why do you think they are important? Just because I think they are important doesn't make it so (unfortunately), so what might you have included to convince your reader that they are important?

    This is extremely minor, but you might trying playing around with your camera settings to remove the auto time/date stamp next time. In this case, that isn't necessary for your "presentation," so anything that might distract your reader you want to eliminate. (Please note this is in the spirit of critique, just like a Language Arts teacher trying to help you improve your writing so that you can be the best communicator possible.)

  2. Great start! I like the easy to follow pictures and the simple language - it's always important to put things into your own words to show just how much you understand.

    Next, I would suggest trying something a touch harder to see if the same "rules" hold true, and what other "rules" you might need to add.