f=[10 16 62.5 100];
x=sqrt(f)
y=[6.6 8.2 17.1 22]; %UTP;
y1=[5.9 7.6 15.7 20.3]; %FTP
c=polyfit(x,y,2)
c1=polyfit(x,y1,2);
h1=polyval (c1,x);
h=polyval(c,x);
d=h-y
d1=h1-y1