write a general matlab code for a second order polynomial regression, on bases of the general least square regression formula.

second order form:

y=a1+ a2X + a3X^2

general regression form:

A=(z^t x z )^-1 (z^t x y)

where...,

A : is the unkown matrix

z : is the coefficient matrix

z^t : is the transpose matrix

y : is the product matrix

^-1 : is the inverse of the matrix

the code must include the sum of :

[observations (n), sum of x, sum of x square , sum of xy ...etc]

note: you can add comments where i should insert x values y or n for intance.

thanks in advance!