Find the center and radius of a circle?

Find the coordinates of the center and the radius of the circle given by the equation

I know is the center which if I am right its but how do I find the radius ?

if I take and expand it out to how do I enter that into Because I think I need to find atleast one coordinate to find my radius?

Re: Find the center and radius of a circle?

Quote:

Originally Posted by

**M670** Find the coordinates of the center and the radius of the circle given by the equation

I know

is the center which if I am right its

but how do I find the radius ?

if I take

and expand it out to

how do I enter that into

Because I think I need to find atleast one coordinate to find my radius?

1. You've done the first step:

expands to

2. Now complete the square(s):

3. Thus the midpoint of the circle is and the radius is

Re: Find the center and radius of a circle?

Quote:

Originally Posted by

**earboth** 1. You've done the first step:

expands to

2. Now complete the square(s):

3. Thus the midpoint of the circle is

and the radius is

Thank You, I was missing my step of completing the squares