13.1 helix

Next let's think about the velocity vector when t = (pi)/2 .

First look at three POINTS:

(1) the "position" POINT P when t=(pi)/2, which is the head/end-point of the path (vector) when t = (pi)/2 ... think of this POINT P as the POINT on the curve when t = (pi)/2

(2) the point that is the head/end of the velocity VECTOR when t = (pi)/2

(3) the origin

Now let's graph the VECTOR for the origin O to the point V

Now let's "move" the vector OV as so it's initial/start point is P (rather than the origin O).

So we are attaching the tail/start point of the velocity vector (when t=(pi)/2) to the point on the curve when t=(pi)/2.

Prof. G: do the "magnetic" explaination !

All done .