BlueTaslem - Can you explain Arm Movement - And the math necessary for it?

I put blue taslem on the title, cuz I want to see if he's able to answer, because he provides more detail and stuff to my questions.

Can you clarify what you mean by "arm movement"? Also, really, you shouldn't direct questions at particular people

I'm sorry, but you explain stuff much better, then many of the other people who answer questions. When I mean arm movement how the arm point towards the mouse like in Call of Robloxia; the arm point towards the mouse cursor.

This is kind of insulting, although I'll grant that Blue does know his math. You should supply your attempts, however.

There are some high-quality free models that demonstrates this feature (such as Youtubes's or TurboFusion's guns). You may try and observe each component of the math behind it and try to interpret what they do. If you have any  questions due to confusion or curiosity, you're always welcome to post here with a sample code.

This question is particularly broad.. not exactly answerable without someone giving you a complete script. You should supply your attempts. I do have a script for this on the site however, if you want to search through my models for it.

Blue is good at explaining, but it's best to have multiple people help you so you. Also, "Arm Movement" doesn't exist. You can see youtube videos on it maybe or free models. We only help people who have something wrong with a script and post it on this website.