clc
clear all
disp('datos ingresados')
x=[280 650 1000 1200 1500 1700]
y=[32.7 453.4 52.15 53.7 52.9 50.3]
grid on
plot(x,y)
n=length(x);
a=[n sum(x) sum(x.^2)
sum(x) sum(x.^2) sum(x.^3)
sum(x.^2) sum(x.^3) sum(x.^4)];
b=[sum(y) sum(x.*y) sum(x.^2.*y)]';
c=inv(a)*b;
disp('la ecuacion es:')
fprintf(' %5.4f *x^2 + %5.4f * x + %5.4f\n ',c(3),c(2),c(1))
%comprobacion
sol=polyfit(x,y,2)
x1=x;
y1=c(3)*x.^2+c(2)*x+c(1);
hold on
plot(x1,y1,'o')