Consider the matrix \[{\text{P}} = \left[ {\begin{array}{*{20}{c}} {\frac{1}{{\sqrt 2 }}}&0&{\frac{1}{{\sqrt 2 }}} \\ 0&1&0 \\ {\frac{{ – 1}}{{\sqrt 2 }}}&0&{\frac{1}{{\sqrt 2 }}} \end{array}} \right]\] Which one of the following statements about P is INCORRECT? A. Determinant of P is equal to 1 B. P is orthogonal C. Inverse of P is equal to its transpose D. All eigen values of P are real numbers

Determinant of P is equal to 1
P is orthogonal
Inverse of P is equal to its transpose
All eigen values of P are real numbers

The correct answer is D.

The determinant of P is equal to 1, since it is a product of three terms, each of which is equal to $\pm 1$.

P is orthogonal, since its transpose is equal to its inverse.

The eigenvalues of P are $\pm i$, which are not real numbers.

Therefore, the incorrect statement is D.