### Home > PC3 > Chapter 10 > Lesson 10.2.2 > Problem 10-127

10-127.

Which of the following equations is the equation of a hyperbola? How can you tell? What is the shape of the graph of the other equation? After you have decided on the shapes, sketch their graphs.

Since the terms are being added, this is an ellipse. The center is at

. The 'horizontal radius' is

and the 'vertical radius' is .

Since the terms are being subtracted, this is a hyperbola. The center is at

. To create the "box", use a 'horizontal radius' of

and a 'vertical radius' of .