# The equation of a circle is #x²+y²+2x-4y-8=0#, what are the co-ordinates of the center and the length of the radius of the circle?

##### 1 Answer

May 5, 2016

Let's first convert to standard form by doing a double completion of square. This form is much easier to work with.

#### Explanation:

In standard form

Therefore, the center is at (-1, 2) and the radius measures 13 units.

Hopefully this helps!