Question

How to find which circle has the smallest area?
The answers are
a) x^2+y^2=12
b)(x-2)^2=y^2=8
c)(x+1)^2+(y+3)^2=6
d)(x+8)^2+(y-9)^2=3

Answer 1

the one with the smallest radius

Answer 2

The general form of a circle of radius r and center (h, k) is :
\( (x - h)^2 + (y - k)^2 = r^2\)
This may help you in considering the radius.