Question

9) Center: (-2,9) Point on Circle: (-5, 18)​

Answer 1

`(x+2)^2+(y-9)^2=` 90

Explanation:

The centre is (-2,9) so the first part of the equation will be (x+2)^2 + (y-9)^2 and to get the second half, you know the point on the circle which you can use to find the radius. So the triangle formed would be 3 long, 9 high and using Pythagoras you can do:

`3^2+9^2=r^2`

9+81=
`r^2\\`

90 =
`r^2`

and this equation ends with r^2 so you can substitute that back into the equation so together it will be

`(x+2)^2+(y-9)^2=` 90