Find the standard matrix for the orthogonal projections onto col(A), and find least squares line y=ax+b (0,1),(1,3),(2,4) and (3,4)

Find the standard matrix for the orthogonal projections onto col(A), Find the least squares line y=ax+b of best fit to the four points(0,1),(1,3),(2,4) and (3,4)

A=enter image description here

A is 3×3 matrix [ 1 1 2] [ 2 1 3] [-1 2 1]

(a)Find the standard matrix for the orthogonal projections onto col(A) *Calculate the inverse of a matrix. *Do not calculate the product of matrices.

(b)Find the least squares line y=ax+b of best fit to the four points(0,1),(1,3),(2,4) and (3,4)