選択した画像 reflection across y=x matrix 593244-How to do reflection across y=x howaavonladywentfromstruggletosuccess

Reflection across the $xz$plane $w_1 = x 0y 0z \\ w_2 = 0x y 0z \\ w_3 = 0x 0y z$ $\begin{bmatrix}1 & 0 & 0 \\ 0 & 1 & 0 \\ ...