# How do you write the equation for a circle with center (2a, a) and touching the y-axis?

##### 1 Answer

Nov 8, 2016

#### Explanation:

If the circle touches the Y-axis then the **radius** of the circle is equal to the horizontal distance from the Y-axis to the center of the circle.

The distance from the Y-axis to the center of the circle is the

So in this case the radius is

The equation for a circle with center

So the equation for a circle with cneter