What is the equation of a circle with center (-4 2) and diameter 6?

Use the general form:-

(x - a)^2 + (y - b)^2 = r^2 where (a, b) is the centre and r = radius

Here the radius = 1/2 * 6 = 3 so r^2 = 9 and we have the equation:-

(x + 4)^2 + (y - 2)^2 = 9 (answer)