# How do you write the equation of the circle where C(1,-3) and D(-3,7) are the endpoints of a diameter?

##### 1 Answer

#### Answer:

#### Explanation:

The midpoint of the diameter

The length of the diameter is given by the Pythagorean Theorem:

which implies that the radius of the circle is

The general formula for a circle with center

In this case:

For verification purposes here is the graph of this circle equation with the given diameter endpoints:

graph{((x+1)^2+(y-2)^2-29)((x-1)^2+(y+3)^2-0.02)((x+3)^2+(y-7)^2-0.02)=0 [-12.53, 12.78, -4.8, 7.86]}