Respuesta :
Answer:
The matrixes are in the explanation box.
1. A mapping of (x,y,z) to (x,y,0)
2. Is a mapping of (x,y,z) to (-x,-y,z)
Step-by-step explanation:
We have the orthogonal projection onto the cy-plane to be a mapping of (x,y,z) to (x,y,0). Then we will have a transformation matrix that has the form below.
[1 0 0]
[0 1 0]
[0 0 1]
For the reflection in the z-axis,it is a reflection of (x,y,z) to (-x,-y,z). Our matrix will then have the form below
[-1 0 0]
[0 -1 0]
[0 0 1]

The matrix that projects into the XY plane is:
[tex]\left[\begin{array}{ccc}1&0&0\\0&1&0\\0&0&0\end{array}\right][/tex]
The matrix that reflects in the z-axis is:
[tex]\left[\begin{array}{ccc}-1&0&0\\0&-1&0\\0&0&1\end{array}\right][/tex]
How to find the transformations?
First, we want to find the transformation that goes from (x, y, z) to (x, y, 0).
Remember that:
[tex](x, y, z)*\left[\begin{array}{ccc}1&0&0\\0&1&0\\0&0&1\end{array}\right] = (x, y, z)[/tex]
That matrix is the identity matrix.
Then, if we want to remove the z component, then we just need to make the last row-column equal to zero, we will get:
[tex](x, y, z)*\left[\begin{array}{ccc}1&0&0\\0&1&0\\0&0&0\end{array}\right] = (x, y, 0)[/tex]
Now we want to make a reflection over the z-axis, this is a rotation of 180° around the z-axis, so it changes the sign of the x and y components:
(x, y, z) to (-x, -y, z)
From this, we conclude that the matrix will be:
[tex](x, y, z)*\left[\begin{array}{ccc}-1&0&0\\0&-1&0\\0&0&1\end{array}\right] = (-x, -y, z)[/tex]
If you want to learn more about matrices, you can read:
https://brainly.com/question/11989522