d
(d) Let $A = \left[ {\begin{array}{*{20}{c}}{\cos 2\theta }&{ - \sin 2\theta }\\{\sin 2\theta }&{\cos 2\theta }\end{array}} \right]$, $|A| = 1$
$adj\,(A) = \left[ {\begin{array}{*{20}{c}}{\cos 2\theta }&{\sin 2\theta }\\{ - \sin 2\theta }&{\cos 2\theta }\end{array}} \right]$
${A^{ - 1}} = \frac{{adj\,(A)}}{{|A|}} = \left[ {\begin{array}{*{20}{c}}{\cos 2\theta }&{\sin 2\theta }\\{ - \sin 2\theta }&{\cos 2\theta }\end{array}} \right]$.