This is my first post, so hello forums . Anyway, I am trying to relearn calculus, took a hiatus for a while, and I am currently taking beginners multi-variable calculus and I hit an example that I do not understand in my book (probably cause my diff/integral calculus could use some boning up ).
This involves Arc Length and Curvature:
r(t) = cos(t)i + sin(t)j + tk from point (1,0,0) to (1,0,2 )
they show that
and then they say "The arc from (1,0,0) to (1,0,2 ) is described by the parameter interval and so [from formula 3], we have...
I do not understand how they got ?
shouldn't it be ?
Thank you for any and all input