Question

For the linear system Ax = b, with A and b defined as

A= [1 2 -1; 2 3 1; -1 -1 -2; 3 5 0]

B= [1; 0; 1; 0]

(a) By hand, calculate the pseudoinverse A+

(b) Use the pseudoinverse to calculate a least squares solution for the

system.

(c) Calculate the least squares solution to the system in MATLAB,

using mldivide (i.e., A\b).

(d) Calculate the size of the error e from each solution, and compare the size of each least squares solution xˆ. How do the errors and sizes compare?

Answer 1

(a)

(b)

(c)

define A and B as shown in question. then use the mldivide function as shown below:

(d)