Exercício 4.27 (b)

> X:=matrix(5,2,[1,1,4,8,9,27,16,64,25,125]);
b:=vector(5,[1.2,0.8,2.4,2.9,3.5]);
XtX:=evalm(transpose(X)&*X);
Xtb:=evalm(transpose(X)&*b);
sol:=vector(2,0):
sol:=Gauss(XtX,Xtb);

> p3:=sol[1]*x^2+sol[2]*x^3;
with(student):
p3x:=makeproc(p3,x);
with(plots):
pplot:=plot(p3x(x),x=1..5):
A:=pointplot({[1,b[1]],[2,b[2]],[3,b[3]],[4,b[4]],[5,b[5]]},axes=BOXED,symbol=circle,title="Exercício 4.27 (b)"):
display(pplot,A);

Warning, new definition for D