The general statement for all circles is:
Given the equation of the circle (x – h)² + (y-k)² = r²,
the center of the circle is located at (h,k), and its
radius has a length of r units.
You should learn that.
Your equation is
(x – 9)² + y² = 484
Since the square root of 484 is 22 and since y can
be written as (y - 0), your equation can be written as
(x – 9)² + (y - 0)² = 22²
Now if we compare that with
(x – h)² + (y - k)² = r²
we see that h = 9, k = 0, and r = 22.
So we make those substitutions in the general statement
about all circles, we get
Given the equation of the circle (x – 9)² + (y - 0)² = 22²,
the center of the circle is located at (9,0), and its
radius has a length of 22 units.
Edwin
