- #1

- 3

- 0

## Main Question or Discussion Point

The unit tangent vector,

**T**(t) =**r**'(t) / ||**r**'(t) || always has length 1. Alright, so how do we get a sense of the length of the actual tangent vector itself? Its direction is easy to imagine, but I can't understand how its magnitude changes along the curve (does it have something to do with curvature?).