## anonymous one year ago Find the standard matrix of a linear transformation that maps a point (x,y,z) in 3 dimensional coordinate space XYZ to its projected point in XY coordinate plane followed by reflection across coordinate axis y.

1. ganeshie8

$(x,y,z) \longrightarrow (x, y, 0) \longrightarrow (-x, y, 0)$

2. anonymous

Wow was it really that easy? so the matrix would be: [-x] [ y] [0] right?

3. ganeshie8

Nope, it should be a 3x3 matrix which maps (x, y, z) to (-x, y, 0)

4. anonymous

Okay can you help me set up how to do that?

5. ganeshie8

try $\begin{bmatrix} -1&0&0\\0&1&0\\0&0&0\end{bmatrix}$

6. anonymous

Okay thanks. I was way over thinking this problem!

7. ganeshie8

np