Question

What is the equation of the circle centered at (-3,2) given that (0,-2) lies on the circle

Answer 1

Problem

What is the equation of the circle centered at (-3,2) given that (0,-2) lies on the circle

Solution

The general equation for a cirlce is given by:

`(x-h)^2+(y-k)^2=r^2`

Where h and k represent the coordinates of the center. For this problem we know that h= -3 and k=2 and we have:

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

Now we can use the point given x=0 and y=-2 in order to find the radius on this way:

`(0+3)^2+(-2-2)^2=r^2`

And solving we have:

`9+16=r^2`
`r=\sqrt[]{25}=5`

And the best answer would be

`(x+3)^2+(y-2)^2=25`