Question

Find the standard form of the equation of the circle with endpoints of a diameter (3,6) and (-9,8).

Answer 1

Hint,
1. add the x coordinates, then divide by two.
2. add the y coordinates, then divide by two.

Answer 2

Better yet, here's a formula that will work:

If you have a line segment AB, with the coordinates of points A and B then the formula

\[AB_{mid} = \frac{x_1+ x_2}{2}, \frac{y_1 + y_2}{2}\]

will give you the coordinates of the midpoint of segment AB