# Math Help - Determine the effect of the following transformations

1. ## Determine the effect of the following transformations

Determine the effect of the following transformations
a) Rotation through pi/2, followed by projection on the Y axis, followed by reflection in the lines y=x.
b) Projection on the X axis followed by reflection in the line y=x.

2. It is easy to find the matrix of the rotation $R$ and the reflection $S$ :

$R \equiv \begin{bmatrix}{0}&{-1}\\{1}&{\;\;0}\end{bmatrix},\quad S \equiv \begin{bmatrix}{0}&{1}\\{1}&{0}\end{bmatrix}$

So,

$S\circ R\equiv \begin{bmatrix}{1}&{\;\;0}\\{0}&{-1}\end{bmatrix}$

that is, $S\circ R$ is the reflection in the $x$ axis.

Try b) .

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