(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Let c(t) be a path of class C1. Suppose that ||c(t)||>0 for all t.

Show that c(t) dot product with d/dt((c(t))/||c(t)||) =0 for every t.

2. Relevant equations

I am having trouble with the derivative of (c(t)/||c(t)||) and how to show that when its dotted with c(t) that it always equals zero.

3. The attempt at a solution

I know that c(t) dotted with c'(t) =0 when ||c(t)||= a constant but dont know how to implement this fact for this problem.

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Dot product of a vector with the derivative of its unit vector

**Physics Forums | Science Articles, Homework Help, Discussion**