Yeah the lift equation you wrote is the one I mentioned in my post. I just put p for rho as that is the notation for freestream density the book I have uses; it has a rotated by a right angle 8 as well, showing it is freestream density.

I understand all you said except how have you pointed out that in fig. 1 (i.e. the graph) the separation ocurs at 30% of the way back from the LE? I would this that it is at 0.2 (i.e. 20%) because that is where the pressure rises. Can you reply on this please? thanks.

Lafayette. thanks for responding to my questions!!!