Understanding Tangent Vectors for Discs: Deciphering (1 -1 0)T

[Leb]

Homework Statement

I do not understand how the vector (1 -1 0)^T represents the axis tangent to the disk at Q.

The Attempt at a Solution

Tried thinking in terms of simple vector addition, but just got another vector in the radial direction...
I mean, (1 -1 0)^T is parallel to a tangent vector to Q, is that sufficient ?

 

[tiny-tim]

Hi Leb!

I do not understand how the vector (1 -1 0)^T represents the axis tangent to the disk at Q.
…
Tried thinking in terms of simple vector addition, but just got another vector in the radial direction...
I mean, (1 -1 0)^T is parallel to a tangent vector to Q, is that sufficient ?

I don't really understand what's worrying you.

don't "the axis tangent to the disk at Q" and "parallel to a tangent vector to Q" mean the same thing?

 

[Leb]

Hi Leb!


I don't really understand what's worrying you.

don't "the axis tangent to the disk at Q" and "parallel to a tangent vector to Q" mean the same thing?

Hello tiny-tim!

Apparently I was a bit rusty with vectors and was not sure if we are free to translate to parallel vectors on top of each other, but thanks !