Hey guys and gals, newbie here, welcome everyone!

I need some help on solving the following problem: (see attached file).

Any help and hints are appreciated, thanks for reading!

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- May 31st 2010, 03:34 AMIukwimPartial derivatives of third order
Hey guys and gals, newbie here, welcome everyone!

I need some help on solving the following problem: (see attached file).

Any help and hints are appreciated, thanks for reading! - May 31st 2010, 03:44 AMProve It
- May 31st 2010, 03:47 AMHallsofIvy
The only reasonable "hint" is "Do it!". Take those third derivatives and put then into the equation to see if it is satisfied.

Is your difficulty with the derivative? What do you get for the first and second derivatives?

Prove It got in ahead of me again! I need to type faster! - May 31st 2010, 08:01 AMIukwim
I was asking because the third derivatives looked terrible and I thought I might be missing some theorems or properties.

It turned out that the solution is rather simple than calculating directly.

The**ln**function can be represented as following:

http://img535.imageshack.us/img535/954/mimetex.gif

And then computing is much easier (otherwise the third derivatives looked terrible).

Thanks for the encouragement, guys!