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

We know that T(t) = r'(t)/||r'(t)||, or equivalently, r'(t) = ||r'(t)||·T(t). Differentiate this equation to find r''(t), then show that

r'(t) x r''(t) = ||r'(t)||^2 · (T(t) x T'(t)).

2. Relevant equations

r''(t) = ||r'(t)||'·T(t) + T'(t)·||r'(t)||

3. The attempt at a solution

I was able to get as far the differentiation above but from there I got stuck. I attempted to cross both sides, which i'm pretty sure needs to be done, but I'm confused how to get the right side of the equation to simplify to the desired form. Any help would be greatly appreciated...Thanks a lot

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# Homework Help: Cross product proof

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