close all; clc; clear; 

% Problem EPage 46
% 
for n=[10,15,20] % for a couple values of n 
  E = c_2_p_10_mk_E(n);
  b = ( 1:n ) .';

  % Part (a): 
  % 
  x_pt_a = ( E \ b ).';
    
  % Part (b): 
  % 
  [L,U] = lu(E);
  y = L \ b; % solve L y = b
  x_pt_b = ( U \ y ).'; % solve U x = y 
  
  disp( sprintf( 'solution for n= %10d', n ) );
  [ x_pt_a ; x_pt_b ] 
end