# Wondering in Math !!!

Discussion in 'Mathematics and Physics' started by engineers feel, Feb 25, 2008.

1. ### engineers feelNew Member

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how are you doing every one ?
I just have a wondering and I hope you help me to get its answer

I've an equation and I want to get the value of Y with respct to X

the equation is

sin ( Y ln(XY) ) + e^(XY^(2)) - 1 = 0

as I told you, I need the value of Y with respct to X

I'm waiting for you ,,,,

Regards

2. ### PapabravoWell-Known Member

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What makes you think that there is a way?

3. ### engineers feelNew Member

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As a matter of fact, there was a challenge between me and my friends
and in my opinion, if we have two variables in one equation
we can easly get the value of one of them with repect to another
so I want you to share me this challenge and I'm sure we can get its answer
if we put some efforts
and I again hope you help me to find the answer

Regards

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5. ### PapabravoWell-Known Member

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Separating variables is not always possible. The odds drop dramatically when transcental functions are involved. I think you have no chance on this one, unless there is someone telling you that there is a solution.

As another example, consider the general conic section

Ay² + By + Cxy + Dx² + Ex + F = 0, for real constants A, B, C, D, E, & F

I dont think you can separate this one either

Last edited: Feb 25, 2008
6. ### engineers feelNew Member

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Thanks to you

7. ### erosenninNew Member

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This is what it looks like...

Just because there is an equation doesn't mean that it is able to be transposed. Like some engineering functions, they are just approximations.

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8. ### bananasiongNew Member

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Hi,
What software are you using to plot this? Excel?

9. ### erosenninNew Member

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MatLAB. Like excel, but better.

10. ### cescoNew Member

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I have some vague memories of functional analysis, but i think that with Taylor series and a bit of accurate calculations you can manage to extract a function which approximates well your function and in which variables are separable.

But my memories are vague, so I'm not completely sure.

11. ### PapabravoWell-Known Member

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I think working with any series expression represented by that function is going to be harder than you can imagine. I'm calling your bluff on this one.
Yuuuuh!

Also as you can see from the plot the function is multivalued, and in a strict sense is not really even a function, much less one that can be separated.

Last edited: Mar 12, 2008