Notice that the general equation of an ellipse does not easily tell us what a certain ellipse looks like. |
On the other hand, the standard equation of an ellipse provides information about the centre coordinates and lengths of the horizontal and vertical axes. |
Recall that this was also true of the general and standard equations of a circle. |
When asked to describe the picture of a circle given its general equation, we rewrote the general equation into standard form using a method called completing the square. |
We use this same method when rewriting the equation of an ellipse from general to standard form. |
Let's look at a few examples. |