# How do you find the center and radius for #x^2 + y^2 - 8x - 2y - 8 = 0#?

##### 1 Answer

Jun 1, 2016

The center is

#### Explanation:

#0 = x^2+y^2-8x-2y-8#

#= x^2-8x+16 + y^2-2y+1 - 9#

#= (x-4)^2+(y-1)^2-3^2#

Add

#(x-4)^2+(y-1)^2 = 3^2#

This is in the form:

#(x-h)^2+(y-k^2) = r^2#

which is the general form of the equation of a circle with centre