function [U,x]=my_solution3(a,b,N,q,p);
x=uniform(a,b,N); % Omioimorfos diamerismos
x_inside=x(2:end-1); %esoterika simeia
h=x(2)-x(1); %yplogismos h
F=zeros(N,1);
for i=1:N
    F(i)=h^2*f(x(i+1));
end
A=my_triag3(N,x_inside,q,p); %triafiagonios pinakas
y=A\F;  %epilisi grammikou sistimatos
U=zeros(N+2,1);
for i=1:N;
    U(i+1)=y(i);
end

