I am trying to solve this question
$D$ is the matrix given by $D = \begin{pmatrix} h & 0 \\ 0 & k \end{pmatrix},$ where $h = 36$ and $k = -3$. What is the lower-right entry in the matrix $D^n$, where $n = 6$?
This is my attempt, but I am stuck half-way as it just doesn't seem right