# Is there a way in Maths formatting of circling a number?

Yup - see below

#### Explanation:

We use the formula for a circle to graph one.

Let's say we want a circle around the origin. We can graph the formula:

$\left({\left(x - 0\right)}^{2} + {\left(y - 0\right)}^{2} - .1\right) = 0$

to get this:

graph{((x-0)^2+(y-0)^2-.1)=0}

Note that if I want a circle at $\left(2 , - 1\right)$ and want the circle to be bigger, I can graph the formula

$\left({\left(x - 2\right)}^{2} + {\left(y + 1\right)}^{2} - .5\right) = 0$

to make that happen:

graph{((x-2)^2+(y+1)^2-.5)=0}

Also note that with the way I've got the brackets set up, we can graph a series of circles (say like we want to graph the two points together and then show the line that connects them by graphing this:

$\left({\left(x - 0\right)}^{2} + {\left(y - 0\right)}^{2} - .1\right) \left({\left(x - 2\right)}^{2} + {\left(y + 1\right)}^{2} - .1\right) \left(y + \frac{1}{2} x\right) = 0$

graph{((x-0)^2+(y-0)^2-.1)((x-2)^2+(y+1)^2-.1)(y+1/2x)=0}

The graphing tool can do so much more as well. I encourage you to search Socratic (the search bar is in the. top right corner of the page) to see how you can make shapes, shade areas, and do other things with the tool.