Hey guys,

Finding hard to solve these derivative:

1) (don't know how to deal with the index -t/2)

2) (this seem confusing as don't know what rule to apply)

3) (not to sure about index agian)

I hope someone can help. Thanks

dadon

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- Apr 29th 2006, 09:22 AMdadonDerivative qus.
Hey guys,

Finding hard to solve these derivative:

1) (don't know how to deal with the index -t/2)

2) (this seem confusing as don't know what rule to apply)

3) (not to sure about index agian)

I hope someone can help. Thanks

dadon - Apr 29th 2006, 09:37 AMCaptainBlackQuote:

Originally Posted by**dadon**

so using the chain rule to do the derivatives:

simplifying:

RonL - Apr 29th 2006, 09:48 AMCaptainBlackQuote:

Originally Posted by**dadon**

By the chain rule this is:

RonL - Apr 30th 2006, 12:57 AMdadonre:
Thanks for the quick response and the general rule! :)

So for 2) is it product and chain together? - Apr 30th 2006, 01:28 AMCaptainBlackQuote:

Originally Posted by**dadon**

so you may need to use the product rule again for the derivative of the

second term on the RHS.

RonL - Apr 30th 2006, 01:38 AMCaptainBlackQuote:

Originally Posted by**dadon**

,

so:

but from the original equation we know that:

,

so substituting this into equation gives:

or rearranging:

RonL - Apr 30th 2006, 08:08 AMdadon
Hi Thanks again!

Both methods should give the same answer? - Apr 30th 2006, 08:23 AMdadon
The implicit way is a much neater, when applying the product and chain rule it gets abit messy that's what I have been trying!