function [x w] = lfd(a,b,alpha,beta,N)
h=(b-a)/(N+1);

% Create the interior samples i=1,2,...N-1
x=(a+h:h:b-h)';

% Create the main diagonal
md = 0;

% Create the subdiagonal
subd = 0;

% Adjust the subdiagonal so that it will work with spdiags.  Use the
% vertcat command.
subd = subd +0;

% Create the superdiagonal
supd = 0;

% Adjust the superdiagonal so that it will work with spdiags.  Use the
% vertcat command.
supd = supd +0;

% Create the tridiagonal matrix A
A=spdiags([subd md supd],-1:1,N,N);

% Create the right hand side vector
rhs=0;
% Adjust the first and last values of rhs
rhs(1)=rhs(1)+0;
rhs(N)=rhs(N)+0;

% Add the first and last values to the vector x
x=vertcat(a,x,b);

% Solve the system for w and then use vertcat to add the first and last
% initial conditions
w=vertcat(alpha,A\rhs,beta);



function y = p(x)
    y=ones(numel(x),1);
    
function y = q(x)
    y=2*ones(numel(x),1);
    
function y = r(x)
    y = cos(x);