(x - 3)² + y² = 121
Ww want to first write it in the form
(x - h)² + (y - k)² = r², which has center (h,k) and radius r
(x - 3)² + y² = 121
The first term is already in the form (x - h)². The second
term is y², so to get it in the form (y - k)², we write it
as (y - 0)²
(x - 3)² + (y - 0)² = 121
To get the last term in the form r² we write 121 as 11²:
(x - 3)² + (y - 0)² = 11²
Now we compare it to
(x - h)² + (y - k)² = r²
and get h = 3, k = 0, r = 11
So the center is (h,k) = (3,0) and the radius is r = 11
Edwin
