3 replies to this topic

[Abdelilah]

Hi all

 

I'm not a genius in math. So, any help is welcome :

 

I've this function :

 

y = a*x^5 + b*x^4 + c*x^3 + d*x^2 + e*x + f

 

My query is how to calculate x depending on y. I mean x=f(y).

 

Thanks in advance.

Edited by Abdelilah, 10 October 2021 - 08:03 AM.

[latexman]

Numerically, using Newton’s method.

[Pilesar]

It may not be the academic way, but I would put the y=f(x) function in Excel and use the 'goal seek' feature to target the y value desired by adjusting 'x'. If it did not find solution the first time, I would use a different initial estimate for 'x'. The Excel goal seek uses Newton's method and is pretty robust.

[breizh]

Hi,

Consider the paper attached within the link :

http://www.scielo.or...2n2/v52n2a9.pdf

 

note : let you try your favorite search  engine as I did .

 

Hope this is helping you

 

Breizh