Answer:
Circumference = πd
where d = diameter
Step-by-step explanation:
When using this formula you don't need to multiply by 2 like you do when using the radius because the diameter is twice the radius of a circle.
i solved that here
http://lianmath.com/what-is-the-turning-of-the-graph-of-fx-x3-2/
I'd say the answer would be 8.
