Question

Is the given point interior, exterior, or on the circle (x + 2)2 + (y - 3)2 = 81?

Q(3, 0)

Answer 1

Take the circle's equation: (x + 2)^2 + (y - 3)^2 = 81 and substitue 3 for x and 0 for y. If the result is less than 81, the point (3,0) lies in the interior of the circle.
If the result is equal to 81, the point (3,0) lies on the circle. If the result is greater than 81, then the point (3,0) lies in the exterior of the circle. @EricReaves