Let A = \left| {\begin{matrix} 5 & {5\alpha } & \alpha \ 0 & \alpha & {5\alpha } \ 0 & 0 & 5 \ \end{matrix} } ight|. If \,\,\left| {{A^2}} ight| = 25, then \,\left| \alpha ight| equals

Question

Let A = \left| {\begin{matrix} 5 & {5\alpha } & \alpha \ 0 & \alpha & {5\alpha } \ 0 & 0 & 5 \ \end{matrix} } ight|. If \,\,\left| {{A^2}} ight| = 25, then \,\left| \alpha ight| equals

Accepted Answer

Answer: A. 1/5 \left| {{A^2}} \right| = 25 \Rightarrow {\left| A \right|^2} = 25 \Rightarrow {\left( {25\alpha } \right)^2} = 25 \Rightarrow \left| \alpha \right| = {1 \over 5}

Let $$A = \left| {\begin{matrix} 5 & {5\alpha } & \alpha \\ 0 & \alpha & {5\alpha } \\ 0 & 0 & 5 \\ \end{matrix} } \right|.$$ If $$\,\,\left| {{A^2}} \right| = 25,$$ then $$\,\left| \alpha \right|$$ equals

Answer

Explanation

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