Problem with finite difference method.

I am trying to implement Finite difference method. I created the tri diagonal matrix, then solved using the command y=A\b. But the same problem, when done through the Thomas algorithm, answer is different from the first one. The curve looks the same, but there are differences in the numerical values. Why is that so?

x=0.0:pi/6:pi;
N=length(x);
h=x(2)-x(1);
%%Creating tridiagonal matrix
A=zeros(N,N);
a=-2/h^(2);%main diagonal 
b=(1/h^(2));%sub diagonal
c=(1/h^(2));%super diagonal
r=(x.*sin(x))';

for i=1:N
    A(i,i)=a;
end
for j=2:N
    A(j,j-1)=b;
    A(j-1,j)=c;
end

%%Solving for y
y=A\r;
y(1)=0;
y(N)=0;


xf=0:pi/50:pi;
sol=2*(1-cos(xf))-xf.*sin(xf)-4*xf/pi;
clf
plot (xf,sol,'r')
hold on
plot(x,y)