# Find the adjoint of the given matrix and verify

Question:

Find the adjoint of the given matrix and verify in each case that $A .(\operatorname{adj} A)=(\operatorname{adj} A)=m|A| .1 .\left[\begin{array}{cc}\operatorname{Cos} \alpha & \sin \alpha \\ \sin \alpha & \cos \alpha\end{array}\right]$

Solution:

Hence Proved

Ans. $\left[\begin{array}{cc}\cos \alpha & -\sin \alpha \\ -\sin \alpha & \cos \alpha\end{array}\right]$