Question

A circle is centered at the point (3.2, 2.1), and has a radius of length 4.3. What is its equation?

Answer 1

`(x-3.2)^2+(y-2.1)^2=18.49`

Explanation:

The equation of a circle is `(x-h)^2+(y-k)^2=r^2`

where `(h,k)` is the center of the circle and `r` is the radius.

`(h,k)=(3.2,2.1)` and `r=4.3`

Substituting gives:

`(x-3.2)^2+(y-2.1)^2=4.3^2`

`(x-3.2)^2+(y-2.1)^2=18.49`