Question

Which identity represents the transpose of transpose property?

Options

• \((A')'=A'\) or \((A^T)^T=A^T\)

• \((A')'=0\) or \((A^T)^T=I\)

• \((A')'=A^{-1}\) or \((A^T)^T=A^{-T}\)

• \((A')'=A\) or \((A^T)^T=A\)

Answer 1

Taking transpose twice gives back the original matrix. Therefore, \((A')'=A\) and equivalently \((A^T)^T=A\).