Question

2 PUNTS

This circle is centered at the origin, and the length of its radius is 2. What is
the circle's equation?​

Answer 1

x^2 + y^2 = 4

Explanation:

The center-radius form (formally called the standard form) of a circle is

(x-h)^2+(y-k)^2=r^2 where (h,k) is the center and r is the radius.

So if we replace (h,k) with (0,0) since the center is the origin and r with 2 since the radius is 2 we get:

(x-0)^2+(y-0)^2=2^2

Let's simplify:

x^2 + y^2 = 4