What would this graph look like: $\displaystyle 3y^2 + 3x^2 + 12y=0$.
I know that it is a circle but how do I work out the center and the radius of it? Thanks in advance.
You should not have been given this problem without a refresher on "Completing the Square". complete the Square on the 'y's and you will be done.
$\displaystyle 3x^2 + 3y^2 + 12y = 0$
$\displaystyle x^2 + y^2 + 4y = 0$
$\displaystyle x^2 + (y^2 + 4y + something) = something$
$\displaystyle 4/2 = 2$
$\displaystyle 2^2 = 4 = something$
$\displaystyle x^2 + (y^2 + 4y + 4) = 4$
I'll leave you the last step.