No.
No.
No.
No. Both foci are always inside the ellipse, otherwise you don't have an ellipse.
No. Both foci are always inside the ellipse, otherwise you don't have an ellipse.
No. Both foci are always inside the ellipse, otherwise you don't have an ellipse.
No, and there are two of them!
False
An ellipse has 2 foci. They are inside the ellipse, but they can't be said to be at the centre, as an ellipse doesn't have one.
An ellipse, a hyperbola.
Foci.
yes
Yes.