Question

Write the equation of the circle with center (−3, 2) and (6, 4) a point on the circle.

Answer 1

`(x-h)^2+(y-k)^2=r^2`
center is (h,k) and radius is r

so

given center=(-3,2)=(h,k)

`(x-(-3))^2+(y-2)^2=r^2`

`(x+3)^2+(y-2)^2=r^2`
find r^2
ok, (6,4) is a point
sub 6 for x and 4 for y and evaluate


`(6+3)^2+(4-2)^2=r^2`

`(9)^2+(2)^2=r^2`

`81+4=r^2`

`85=r^2`


the equation is

`(x+3)^2+(y-2)^2=85`

Answer 2

radius=sqrt(2^2+9^2)
r=9.22
equation
(x+3)^2+(y-2)^2=9.22^2
(x+3)^2+(y-2)^2=85