Answer:

Explanation:
Given that the endpoints of the diameter of the circle are (3, -7) and (5, 7), we know that the center of these two points must represent the center of the circle. To determine this, we can use the midpoint formula to find the center,
.



Now, with this in mind, we can figure out the radius,
, of the circle. To do this, we can use the distance formula (or pythagorean theorem) from the center point
to any of the two given endpoints, since we know the distance from either endpoint to the center is equal.
(
and
represent the x and y of the center, while
and
represent the x and y of either endpoint)
(Using point (5,7))



Knowing both the center,
, and the radius,
, we can now write a formula for the circle. The formula for a circle is
, where
represent the center, and
is the radius, as always.
Finally, we get the equation:


Below is a graph visualizing the circle and the 2 endpoints.