clear, clc
x=(1.6:0.8:3.2)';
y=[4.4 5.2 2]';
%c1*x^2+c2*x+c3=y
A=[x.^2 x ones(size(x))];
c=A\y
xplot=(1.5:0.1:3.3)';
yplot=c(1)*xplot.^2+c(2)*xplot+c(3);
plot(xplot,yplot,x,y,'*')