How to square a vector?

How to square a vector?

It's the square of the module of the vector

Two judgment questions about space vector!
1. If all the unit vectors in space are moved to the same point as the starting point, their ending points form a circle
2. A space vector is a directed line segment in space

Wrong. It's the ball, not the circle
yes

Simple vector judgment
Why are the modules of vector AB and Ba not equal?

It's equal
When the vector becomes a "module", we don't consider the direction, we just look at the length
So AB = ba
Module is the length, the length of vector, scalar, that is, non direction
So it's equal