Another College Algebra Question?
The question is:
x^2 + y^2 - 12x -2y +21 = 0
(That's x and y squared)
How do I find the center and the radius?
Thank You!
The question is:
x^2 + y^2 - 12x -2y +21 = 0
(That's x and y squared)
How do I find the center and the radius?
Thank You!
hayharbr
Favorite Answer
You complete the squares for x and y, and move the constant terms to the right of the = sign. Eventually this constant term will be radius squared.:
x^2 - 12x + y^2 - 2y = -21
(x - 6)^2 [gives an extra 36] + (y - 1)^2 [gives an extra 1] = -21 + 36 + 1
(x - 6)^2 + (y - 1)^2 = 16
so center = (6,1) and radius = 4