# How do you find the center and radius of the ellipse with standard equation #x^2+6x+y^2-8y-11=0#?

##### 1 Answer

Feb 14, 2015

First of all this is not an equation of an ellipse, but it is the equation of a circle (even if a circle can be defined as a "particular" ellipse).

The answer is:

It is possible to answer to the question in two ways.

The first, simplier, is remembering some formulas:

Equation of a circle:

center:

radius:

In our case:

so:

C(-3,4) and

The second way is completing the squares:

so: