Linear Algebra 21h: The Matrix that Represents an Arbitrary Rotation in 3D

[nilkrem]

I was caulking my bathroom window this morning. Kept dropping the damn tube and had to reposition it each time. (Call me a stickler but I like to keep the label facing me.) But using the simple tricks I learned here, no problem!

[jeremygribben]

Thank you for these videos, great teacher, finally rotations in 3D make intuitive sense!

[prasadvaidya]

The angles psi is for rotation around the x axis. The how are you using it for representing Rz matrix with parameter Rz(psi)?

[mandeepsingh]

It was a great lecture but I think that the 3X3 matrix form of the R matrix which you show (2:32) contains Rx Ry Rx instead of Rz Ry Rz

[tangolasher]

As you can see, people do rotations by simply concatenating the 3 elementary rotation matrices about the three axes, as below:

So I'm confused about your different approach.

[tangolasher]

@MathTheBeautiful Shouldn't the matrix be a concatenation of rotating about Z, then Y, then X? Why are you rotating about Z twice?

[ahmet-salih-cagatay]

2:00 why
Rz*Ry*Rz?

Shouldn't it be like this?

Rx*Ry*Rz