Math Is Fun Forum

Anjali John

Guest

total derivative

Hi

Can anyone help me with this:want to know the total derivative (second order) of a function F of 3 variables  (L,M1,M2):
   the function is as follows:

      F = L /(M2 - M1 + 1 / M2 - 1 / M1)

  I want d2(F).

thanks
Anjali

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: total derivative

Hi Anjali John;

With respect to what?

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Anjali John

Guest

Re: total derivative

Hi

actually I need the total derivative ,just d2,not wrt any variable

Bob

Administrator

Registered: 2010-06-20

Posts: 10,583

Re: total derivative

hi Anjali John,

But it has to be!  If you graph your function with 'L' on the up axis then what goes across?  That's what it is 'with respect to'.

Then the first derivative is the gradient function for that graph and the second derivative is the gradient function of that graph.  That's what derivative means.  [purists may protest that other definitions are possible, but they all have to equate to this]

Maybe it would help if you gave more details of where this function came from and what you want to do with it next.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob