problem 4. (30 points)
Consider the second order linear two point boundary value problem,
\[
\left\{\begin{array}{c}
-u^{\prime \prime}(x)+2 u(x)=1, x \in[0,1] \\
u(0)=0, u(1)=1
\end{array}\right.
\]
give the numerical differectiation formulas and solve it.