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

if a curve has the property that the position vectorr(t) is always perpendicular to the tangent vectorr'(t). show that the curve lies on a sphere with center the origin.

2. Relevant equations

3. The attempt at a solution

I'm not quite sure how to prove this.

I can writer'(t)[itex]\bullet[/itex]r(t)=0 but expansion doesn't yield anything seemingly useful.

What direction should I look in?

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# Homework Help: Proof of r(t) and r'(t) orthogonal on a sphere

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