# How do you identify the center and the radius of the circle with equation x^2 + (y - 5)^2= 9?

Oct 21, 2016

#### Explanation:

If you write it in this form:

${\left(x - 0\right)}^{2} + {\left(y - 5\right)}^{2} = {3}^{2}$

And then compare it with the standard form:

${\left(x - h\right)}^{2} + {\left(y - k\right)}^{2} = {r}^{2}$

where $\left(h , k\right)$ is the center and $r$ is the radius.

It is easy to observe that the center is $\left(0 , 5\right)$ and the radius is $3$.