Question

Write an equation of the circle with center (-7, 4) and radius 8.

Answer 1

answer

(x+7)^2 + (y-4)^2 = 64

set up equation

the equation of a circle is (x - h)^2 + (y - k)^2 = r^2

where h is the center x coordinate and k is the center y coordinate

values

from the point (-7,4) we know that h = -7 and k = 4

since the radius is 8, r^2 = 8^2 = 64

plug in values

now that we have all the values, we plug them into (x - h)^2 + (y - k)^2 = r^2

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

(x - (-7))^2 + (y-4)^2 = 64

(x+7)^2 + (y-4)^2 = 64