How do you write an equation of a circle with diameter that has endpoints (-7,-2), and (-15,6)?

1 Answer
Aug 2, 2017

The equation of the circle is (x+11)^2+(y-2)^2=32(x+11)2+(y2)2=32

Explanation:

The points on the diameter are A=(-7,-2)A=(7,2) and B=(-15,6)B=(15,6)

The midpoint of ABAB is the center of the circle

O=(((-7)+(-15))/2, ((-2)+(6))/2)=(-11,2)O=((7)+(15)2,(2)+(6)2)=(11,2)

The radius of the circle is

r^2=((-7+11)^2+(-2-2)^2)=(4^2+4^2)=32r2=((7+11)2+(22)2)=(42+42)=32

The equation of the circle is

(x+11)^2+(y-2)^2=r^2=32(x+11)2+(y2)2=r2=32

graph{(x+11)^2+(y-2)^2=32 [-23.04, 2.27, -3.43, 9.24]}