\subsection{Problem 8} Let \begin{equation*} \matr{A} = \begin{bmatrix} \phantom{-}1 & -1 & \phantom{-}0 & \phantom{-}0 \\ -1 & \phantom{-}2 & -1 & \phantom{-}0 \\ \phantom{-}0 & -1 & \phantom{-}2 & -1 \\ \phantom{-}0 & \phantom{-}0 & -1 & \phantom{-}2 \end{bmatrix} \end{equation*} Check whether the symmetric matrix $\mathbf{A}$ is positive-definite. If so, apply the Cholesky factorization. Then, compute its inverse. \lstinputlisting[style=Matlab-editor]{problems/Problem8.m}