Question

please help!! a circle has a diameter with endpoints (3,-2) and (9,-8). what is the equation of a circle ????

Answer 1

First, can you find the distance between those 2 points ?

Answer 2

this shows how
http://www.purplemath.com/modules/distform.htm

Answer 3

If you can find the distance between the two points, then you know the length of the diameter because they tell you the points are at each end of a diameter.

the radius will be 1/2 of the diameter.

the point exactly 1/2 way between the two points is the center of the circle.
to find the middle point, find the average of the x values, and the average of the y values

(the average of 2 numbers: add them up and divide by 2

Answer 4

wait is the answer (x+6)^2+(x-5)^2=r^2 ??