Exercise 9.3

Answers

\begin{array}{l} Z & = [\begin{matrix} z_{1}^{T} \\ \dots \\ z_{N}^{T} \end{matrix}] \\ = [\begin{matrix} {(D x_{1})}^{T} \\ \dots \\ {(D x_{N})}^{T} \end{matrix}] \\ = [\begin{matrix} x_{1}^{T} D^{T} \\ \dots \\ x_{N}^{T} D^{T} \end{matrix}] \\ = [\begin{matrix} x_{1}^{T} D \\ \dots \\ x_{N}^{T} D \end{matrix}] \\ = XD \end{array}

\begin{array}{l} Z^{T} Z & = {(XD)}^{T} XD \\ = D^{T} X^{T} XD \\ = D X^{T} XD \end{array}

niuers

2021-12-08 10:20