1.)f(x,y) = arctan(y/x) fx(2,3)

how would I do this?

2.) f(x,y) = ln(x+ sqrt(x^2+y^2) ) fx(3,4)

1/(+ sqrt(x^2+y^2) * 1+ 1/2(x^2 + y^2) * 2x

is that correct for #2?

Thanks

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- November 12th 2008, 07:15 PMkhuezyneed help on partial derivatives
1.)f(x,y) = arctan(y/x) fx(2,3)

how would I do this?

2.) f(x,y) = ln(x+ sqrt(x^2+y^2) ) fx(3,4)

1/(+ sqrt(x^2+y^2) * 1+ 1/2(x^2 + y^2) * 2x

is that correct for #2?

Thanks - November 12th 2008, 07:21 PMChris L T521
- November 12th 2008, 07:23 PMkhuezythanks
i just plug in x and y into that equation right?

- November 12th 2008, 07:24 PMkhuezythanks
how would I do this?

2.) f(x,y) = ln(x+ sqrt(x^2+y^2) ) fx(3,4)

1/(+ sqrt(x^2+y^2) * 1+ 1/2(x^2 + y^2) * 2x

is that correct for #2? - November 12th 2008, 07:30 PMChris L T521
- November 12th 2008, 07:31 PMChris L T521
- November 12th 2008, 08:08 PMkhuezyhi again
Find all the second partial derivatives of

v = xy/(x-y)

could you quickly show me the steps to see if I did it correctly?

Thanks again - November 12th 2008, 08:28 PMChris L T521
- November 13th 2008, 07:53 AMkhuezyi got the fxx and fyy
but I don't get how you did the fyy/fxx

aren't you suppose to the the derivative of fx

it looks like you took it from the f(x,y) instead of fx(x,y) - November 13th 2008, 01:32 PMMathstud28