Difference between a hyperbola and ellipse

This was a comment that I made regarding Joyce's BOB post.



Joyce,

After reading your BOB post, I can see that you are having troubles with the differences between the standard form of ellipse and hyperbola. They are very similar and sometimes hard to distinguish because Mr. K might algebraically massage them and make them look harder than they actually are. I think that there is only one difference between them. On a ellipse the terms are suppose to have the same signs. On the other hand, on the hyperbola the terms should have opposite signs. To further enhance your learning about this you can check this out: http://people.richland.edu/james/lecture/m116/conics/conics.html