Question

What is the equation for a circle with center (2, -3) and radius of 6?

Answer 1

The general formula for a circle is:
x^2 + y^2 = r^2

Since the r^2 = 36, we know the first two options are incorrect 

If the circle's centre is at (2, -3), the numbers being squared should be the negative of the coordinate

So, the final answer is (x-2)^2 + (y+3)^2 = 36