I am translating Math For Dummies slideshow into a printable format and when going through the slides I am having a problem with understanding some things.

Hopefully this is clear.

If what I am showing here is correct for slide 40 where

quatA = Vector3f(1, 0, 0)

quatB = Vector3f(-1, 0, 0)

quatC = Vector3f(0, 0, 1)

```
Slide 40
Quaternion quatA = new Quaternion();
quatA.fromAngleAxis(-FastMath.HALF_PI, Vector3f.UNIT_Z);
-90 deg around Z axis
(Y) Y
| -z | -z
| / | /
-x ------+------ X -x ------+------ (X)
/ | / |
Z | Z |
-y -y
Before After
quatA = Vector3f(1, 0, 0)
Quaternion quatB = new Quaternion();
quatB.fromAngleAxis(-FastMath.HALF_PI, Vector3f.UNIT_Y);
-90 deg around Y axis
Y Y
| -z | -z
| / | /
-x ------+------ X (-x) ------+------ X
/ | / |
(Z) | Z |
-y -y
Before After
quatB = Vector3f(-1, 0, 0)
Quaternion quatC = quatA.mult(quatB);
-90 deg around Z axis & -90 deg around Y axis
(Y) Y Y
| -z | -z | -z
| / | / | /
-x ------+------ X -x ------+------ (X) -x ------+------ X
/ | / | / |
Z | Z | (Z) |
-y -y -y
Before Step 1 Step 2
quatC = Vector3f(0, 0, 1)
```

Then is this correct where Vector3f vectorB = quatC.mult(vectorA);?

vectorB = Vector3f(0, -1, 0)

```
=======================================================
Slide 41
Vector3f vectorA = new Vector3f(0, 1, 0);
(Y)
| -z
| /
-x ------+------ X
/ |
Z |
-y
Before
vectorA = Vector3f(0, 1, 0)
Vector3f vectorB = quatC.mult(vectorA);
90 deg around X axis
Y Y
| -z | -z
| / | /
-x ------+------ X -x ------+------ X
/ | / |
(Z) | Z |
-y (-y)
Before After
vectorB = Vector3f(0, -1, 0)
```

Slide 42 and 45 shows it as vectorB = Vecotr3f(0, 0, 1).

```
=======================================================
Slide 42 & 45
(Y) Y
| -z | -z
| / | /
-x ------+------ X -x ------+------ X
/ | / |
Z | ( Z) |
-y -y
Before After
Vector3f(0, 0, 1)
```