Question 165751
I am hoping you can help.  I have to find an equation of the circle with center 
{{{matrix( 1,3, "(-2", ",", "3)" )  }}} and radius of {{{sqrt(6)}}}. 
The formula I am using is {{{r^2=(x-h)^2+(y-k)^2}}}
I have {{{(x+2)^2+(y-3)^2=36}}}.
Is this correct?

<pre><font size = 4 color = "indigo"><b>

No it isn't. The left side is correct, but the
right side is incorrect.  That's because 

{{{r=sqrt(6)}}}, and so 

{{{r^2=(sqrt(6))^2}}}, or

{{{r^2=6}}}, not {{{matrix(1,1,cross(r^2=36))}}} 

So the answer should be

{{{(x+2)^2+(y-3)^2=6}}}

Edwin</pre>