MCQ
The inverse of $\left[\begin{array}{cc}1 & \cos \alpha \\ -\cos \alpha & -1\end{array}\right]$is ______.
- A$\left[\begin{array}{cc}1 & \cos \alpha \\ -\cos \alpha & -1\end{array}\right]$
- B$-\sec ^2 \alpha\left[\begin{array}{cc}1 & -\cos \alpha \\ -\cos \alpha & 1\end{array}\right]$
- C$\operatorname{cosec} c^2\left[\begin{array}{cc}1 & -\cos \alpha \\ -\cos \alpha & 1\end{array}\right]$
- ✓$\operatorname{cosec}{ }^2 \alpha\left[\begin{array}{cc}1 & \cos \alpha \\ -\cos \alpha & -1\end{array}\right]$
