Find an equation that satisfies the stated conditions center

Find an equation that satisfies the stated conditions center c(8, -9) radius 4

Solution

equation of a circle whose center is (h, k) and radius is r, is given by:

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

(h, k) = (8, -9)

r = 4

So equation will be

(x - 8)^2 + (y - (-9))^2 = 4^2

x^2 - 16x + 64 + y^2 + 18y + 81 = 16

x^2 + y^2 - 16x + 18y + 129 = 0