How to solve

  • Thread starter natski
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  • #1
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Main Question or Discussion Point

Does anyone know how you would go about solving:

a + b*x + x^(-y) + c*x^(-2y) + d*x^(1-2y)=0

solving for x?
 

Answers and Replies

  • #2
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can you give more information, on whad do a, b, c, d, x and y represent. Are some of them variables,functions, series, or merely constants?
maybe this information would be helpful to me, and to others also who have more expertise.
 
  • #3
uart
Science Advisor
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Does anyone know how you would go about solving:

a + b*x + x^(-y) + c*x^(-2y) + d*x^(1-2y)=0

solving for x?
Sure. It's real easy.

a = -b*x - x^(-y) - c*x^(-2y) - d*x^(1-2y)

If that's not the answer you were expecting then how about specifying which variable you want to solve for.
 
Last edited:
  • #4
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  • #5
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Does anyone know how you would go about solving:

a + b*x + x^(-y) + c*x^(-2y) + d*x^(1-2y)=0

solving for x?
i guess natski already stated that he wants to solve for x.
 
  • #6
uart
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solving for x?
Whoops, that will teach me to read all of the post and not skip the last line.

Sorry, that'ss a transcendental equation in x, so there will be no closed form solution.
 
Last edited:
  • #7
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ej uart how do u determine wheather it is transcendental equation in x?
 
  • #8
uart
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ej uart how do u determine wheather it is transcendental equation in x?
Oh yeah it's not transcendental in x. If y is an integer it's a polynomial in x.
 
  • #9
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Um well y is a constant but a,b,c,d are functions of say z. So I want x=function of z or a function of a,b,c,d in this case. I tried to solve numerically for lots of different values of z, plot it and then fit a function to the plot. This worked except for my answer didn't agree with what it should. So I was hoping for a neater algebraic solution.
 
  • #10
uart
Science Advisor
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So I was hoping for a neater algebraic solution.
Well there might be some partiucular values of "y" for which it can work, but in general I don't think it's going to be possible.
 
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