SOLUTION: Find the radius of the circle defined by the equation x^2+y^2+12x+8y+16=0 Is kinda confused on how to solve, please help.

Algebra ->  Circles -> SOLUTION: Find the radius of the circle defined by the equation x^2+y^2+12x+8y+16=0 Is kinda confused on how to solve, please help.      Log On


   

Question 372624: Find the radius of the circle defined by the equation x^2+y^2+12x+8y+16=0
Is kinda confused on how to solve, please help.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi,

The standard equation of a circle with center C(h,k) and radius r is :

%28x+-+h%29%5E2+%2B+%28y+-+k%29%5E2+=+r%5E2

Find the radius

completing the squares

x^2+y^2+12x+8y+16=0

(x+6)^2 + (y+4)^2 -36 -16 +16 = 0

(x+6)^2 + (y+4)^2 = 36 = 6^2

radius is 6, the center of the circle (-6,-4)