Bounding Rectangle for an Ellipse

Date: 6/28/96 at 9:36:18
From: The.Carl.Group@dns2.noc.best.net, Inc.
Subject: Bounding Rectangle for an Ellipse

Dear Dr. Math,

I work for a multimedia lab in Cupertino, CA.  I am currently working 
on programs to transition between two screens on the PC.  My question
involves Ellipses: I would like to know if there is a general equation 
for a bounding rectangle of an ellipse.  I found your general equation 
for an ellipse, but I am having trouble finding its related rectangle.  

Thank You,

Matthew Carl
The Carl Group, Inc.
Intern Developer

Date: 6/28/96 at 14:53:11
From: Doctor Ethan
Subject: Re: Bounding Rectangle for an Ellipse

Well, if you have the general equation for the ellipse then you have 
the center point and you have the partial radia values  (usually a 
and b).

Then if (x,y) is the center, (x-a,y-b) (x-a,y+b) (x+a,y-b) (x+a y+b)
are the corners of the rectangle that you need.

Hope that helps.

-Doctor Ethan,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/