Question

1. Find the coordinates of the center and the measure of the radius for a circle whose equation is

(x - 8) + (y + 4) = 12

Answer 1

the center of this circle is (8, -4) and the radius is 2√3.

Explanation:

Compare this equation

(x - 8) + (y + 4) = 12 Don't forget to type in the " ^ " symbol to indicate exponentiation.

(x - 8)^2 + (y + 4)^2 = 12

to the standard equation of a circle with center at (h, k) and radius r:

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

In this way we learn that h = 8, k = -4 and r^2 = 12 (or r = 2√3).

Then the center of this circle is (8, -4) and the radius is 2√3.