# How do you write an equation for a circle with Centre at (-1,- 6) with radius 1/3?

Jun 21, 2016

${\left(x + 1\right)}^{2} + {\left(y + 6\right)}^{2} = \frac{1}{9}$

#### Explanation:

The standard form of the equation of a circle is.

$\textcolor{red}{| \overline{\underline{\textcolor{w h i t e}{\frac{a}{a}} \textcolor{b l a c k}{{\left(x - a\right)}^{2} + {\left(y - b\right)}^{2} = {r}^{2}} \textcolor{w h i t e}{\frac{a}{a}} |}}}$
where (a ,b) are the coordinates of the centre and r, the radius.

here a = -1 , b = -6 and r $= \frac{1}{3}$

Substitute these values into the standard equation.

$\Rightarrow {\left(x + 1\right)}^{2} + {\left(y + 6\right)}^{2} = \frac{1}{9} \text{ is the equation of the circle}$