Question

If \( A(t) = \begin{pmatrix} \cos t & \sin t \\ -\sin t & \cos t \end{pmatrix} \), then the product of \( A(t) \) and \( A(-t) \) is

• A. Identity matrix
• B. \( A^2(t) \)
• C. Null matrix
• D. \( A^2(-t) \)

Hint:

Rotation matrices satisfy \( A(t)A(-t) = I \), since they represent inverse rotations.

Answer 1

The Correct Option is A