Find the diameter of the circle (x - 4) 2 + (y + 6) 2 = 16

When the equation is written in this form, the left side shows

where the center of the circle is, and the right side is the square

of the radius.

The center of this circle is at (4, - 6), and its radius is √16 = 4.

So its diameter is 8 units.