X is a variable
6 is a constant
3 is a coefficient
Well first are you trying to factor it?
Answer:

Step-by-step explanation:
To convert an equation of rectangular shape to polar form use the following equivalences



In this case we have the following equation.

First we expanded the expression

Now we know that
,
and 
So

Answer:
I think the answer is C, 0.7777... its 0.77777778..