Question

What is the equation of a circle with the center (3,1) and radius of 4?

Answer 1

`(x-3)^2+(y-1)^2=16`

Explanation:

The format for the equation of a circle is

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

where `(h,k)` is the center and `r` is the radius. We can just plug in values and solve from here:

`(x-3)^2+(y-1)^2=4^2`
`(x-3)^2+(y-1)^2=16`