Question

What is the radius of the circle with this equation of (x-5)2+(y+7)2=8

Answer 1

2√2

Explanation:

compare this equation with the standard equation of a circle centered at (h, k) with radius r:

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

(x - 5)^2 + (y + 7)^2=8

Clearly, r^2 = (radius)^2 = 8, and so the radius, r, is √8, or 2√2