This function determines a=[a1, a2, ...an] to solve the airfoil polynomial.
Zn=an(p)*X^(n-1/2), where n is the number of coordinates for the upper or
lower surface.
Input is a vector of PARSEC parameters p=[p1, p2, ...pn] where
p1=rle
p2=Xup
p3=Yup
p4=YXXup
p5=Xlow
p6=Ylow
p7=YXXlow
p8=yte
p9=delta yte (t.e. thickness)
p10=alpha te
p11=beta te
Information on the PARSEC airfoil parameterization is available at: http://www.as.dlr.de/hs/h-pdf/H141.pdf