Is this equation right?

  • #1
[tex]\underbrace{d}_{dt}[/tex] ([tex]\dot{x}[/tex])[tex]^{2}[/tex] = 2[tex]\ddot{x}[/tex] ??? or is it just 2[tex]\dot{x}[/tex] ?
 

Answers and Replies

  • #2
tiny-tim
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welcome to pf!

hi blueberrypies! welcome to pf! :smile:

neither :redface:

use the chain rule :wink:
 
  • #3


nevermind. I'm going to work on this more.
 
  • #4
Alright, I still haven't figured this out so if anyone can help point out what I'm missing I would greatly appreciate it.

My book has this
attachment.php?attachmentid=31450&stc=1&d=1295467586.png



But I don't get this. Shouldn't it be
attachment.php?attachmentid=31451&stc=1&d=1295467716.png
 

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  • #5
tiny-tim
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no, that would be ∂L/∂t

for ∂L/∂θ', remember that θ' is just a symbol, you can replace it by x (or anything), and forget the ' :wink:
 
  • #6
no, that would be ∂L/∂t

for ∂L/∂θ', remember that θ' is just a symbol, you can replace it by x (or anything), and forget the ' :wink:

Ohhh!

I see what you are saying :) Thanks!
 

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