Question

What is the equation of the circle with a center at `(4 ,1 )` and a radius of `2`?

Answer 1

I found: `x^2+y^2-8x-2y+13=0`

Explanation:

You can use the general equation for a circle of center at `(h,k)` and radius `r` as:
`(x-h)^2+(y-k)^2=r^2`
with your data:
`(x-4)^2+(y-1)^2=2^2`
`x^2-8x+16+y^2-2y+1-4=0`
`x^2+y^2-8x-2y+13=0`