4. Verify the square of the matrices is an unit matrix

Answer variants:

[\begin{array}{l} \cos^{2} θ & 0 \\ 0 & \cos^{2} θ \end{array}]

[\begin{array}{l} \sin^{2} θ & 0 \\ 0 & \sin^{2} θ \end{array}]

[\begin{array}{l} \cos^{2} θ + \sin^{2} θ & 0 \\ 0 & \cos^{2} θ + \sin^{2} θ \end{array}]

[\begin{array}{l} 1 & 0 \\ 0 & 1 \end{array}]

A = [\begin{array}{l} \cos θ & 0 \\ 0 & \cos θ \end{array}]

B = [\begin{array}{l} \sin θ & 0 \\ 0 & \sin θ \end{array}]

then show that \(A^2 + B^2 = I\).

\(A^2 =\)

\(B^2 =\)

\(A^2 + B^2 =\)

\(=\)

\(= I\)

Did you find an error?