What is the equation of the circle with a center at (7 ,1 ) and a radius of 2 ?

1 Answer
Apr 24, 2016

y =+- \sqrt(4-(x²-14x+49))+1.

Explanation:

For a circle with center (h,k) and radius r:

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

So

(x-7)^2+(y-1)^2 = 4

x^2-14x+49+y^2-2y+1 = 4

(y-1)^2 = 4-(x^2-14x+49)

(y-1) =\sqrt{4-(x^2-14x+49)}

graph{(x-7)^2+(y-1)^2 = 4 [-1.42, 11.064, -2.296, 3.944]}