Quick question about deriving these vectors on the notes: First this is the vector:
http://tutorial.math.lamar.edu/Classes/CalcIII/VectorArcLength_files/eq0010M.gif

How did they derive that to get this:
http://tutorial.math.lamar.edu/Classes/CalcIII/VectorArcLength_files/eq0012M.gif

I'm not talking about the magnitude, but the one above the magnitude, the result of the derivation of the vector.

Question

Quick question about deriving these vectors on the notes: First this is the vector: 
http://tutorial.math.lamar.edu/Classes/CalcIII/VectorArcLength_files/eq0010M.gif

How did they derive that to get this:
http://tutorial.math.lamar.edu/Classes/CalcIII/VectorArcLength_files/eq0012M.gif

I'm not talking about the magnitude, but the one above the magnitude, the result of the derivation of the vector.

anonymous · Answer

Anyone? Cmon, I think it has to do with the chain rule.