
Calculus Calculus Math Forum 
 LinkBack  Thread Tools  Display Modes 
May 29th, 2009, 04:23 AM  #1 
Newbie Joined: May 2009 Posts: 2 Thanks: 0  Nested partial derivatives, ('chain rule'?)
Greetings. I'm slogging through some basic quantum mechanics at the moment, and as one could expect it is largely the level of difficulty of the mathematics that decides my progress rate. The last operation that has got me a bit stumped occurs when calculating the commutators for the angular momentum operators. Looking at the solution manual, a key bit of information is this: Now, I can see how would make sense, the outermost operation is derivation with regard to Z, so that cancels the Z in the nested expression, right? I can also kind of agree with Indeed, that would be my initial 'naive' interpretation. Now, what I can't get my head around is: How can it be both? Any light being shed on this matter would be greatly appreciated. Thanks in advance! 
May 29th, 2009, 04:30 AM  #2 
Senior Member Joined: May 2008 From: York, UK Posts: 1,300 Thanks: 0  Re: Nested partial derivatives, ('chain rule'?)
This is actually a simple application of the product rule for differentiation: 
May 29th, 2009, 04:49 AM  #3 
Newbie Joined: May 2009 Posts: 2 Thanks: 0  Re: Nested partial derivatives, ('chain rule'?)
The product rule, D'oh! *smacks forehead* Should have noticed that right away, but somehow several del operators together generate blinding death rays or something, preventing me from seeing the obvious... Thanks a lot! (Also for giving the quickest answer I ever got from the inernet. ) 

Tags 
chain, derivatives, nested, partial, rule 
Search tags for this page 
Click on a term to search for related topics.

Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Partial differention by the chain rule?  84grandmarquis  Calculus  1  October 21st, 2013 04:08 AM 
Can anyone explain CHAIN RULE in Derivatives  praneeth101  Calculus  5  December 15th, 2012 12:30 PM 
Derivatives: Chain Rule  Interest  lilwayne  Calculus  2  October 1st, 2010 06:36 PM 
Chain rule in partial Differentiation  mia6  Calculus  1  April 8th, 2010 07:22 AM 
Chain RULE and higher derivatives!! Anyone?  mezzeric  Calculus  1  February 22nd, 2010 02:27 PM 