Question

Write the standard equation of a circle with center (−4, 0) and radius 3.

Answer 1

The standard equation of a circle:

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

We have the center (-4, 0) → h = -4 and k = 0, and the radius r= 3. Substitute:

$(x-(-4))^2+(y-0)^2=3^2\\\\\boxed{(x+4)^2+y^2=9}$