# How do you find the equation of a circle passes through the origin and has its center at (-1,-9)?

##### 1 Answer

Jun 20, 2016

#### Explanation:

If a circle has a center at

then it has a radius of r=

the general formula for a circle with center

So in this particular case:

or

graph{(x+1)^2+(y+9)^2=82 [-24.15, 21.45, -21.76, 1.06]}