Find the maximum value of `|[1, 1, 1],[ 1, 1+sintheta,1],[ 1, 1, 1+costheta]|`

Explanation

To find the maximum value of the determinant

\[
D = \begin{vmatrix}
1 & 1 & 1 \\
1 & 1 + \sin \theta & 1 \\
1 & 1 & 1 + \cos \theta
\end{vmatrix},
...