Answer:
Radius length: √5
Standard Form (Equation): (x + 4)^2 + y^2 = 5
Step-by-step explanation:
First we will determine the radius;
Center: (-4, 0)
Point on Circumference: (-2, 1)
d = √(-2 - (-4))^2 + (1 - 0)^2 = √(2)^2 + (1)^2
= √4 + 1 = √5
Therefore the radius is of length √5
Now the equation of a circle is in the form ((x - h)^2 + (y - k)^2) = r^2. The center is in the form (h,k) and r is the radius. Given this our equation would be (x - (-4))^2 + (y - 0)^2 = (√5)^2, or [simplified] (x + 4)^2 + y^2 = 5.
