Hello, i dont know if its possible but can someone simply explain me how to solve a third degree equation with numerical analysis?

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- January 16th 2011, 11:59 AMNrtNumerical analysis
Hello, i dont know if its possible but can someone simply explain me how to solve a third degree equation with numerical analysis?

- January 16th 2011, 12:04 PMpickslides
Are you looking to find the roots of a third degree polynomial with a numerical method?

- January 16th 2011, 12:07 PMNrt
Yes.

- January 16th 2011, 12:15 PMpickslides
Ok, what methods have you been taught or is this independent learning (happy to suggest some methods), either is fine, do you have a polynomial in particular that needs solving?

- January 16th 2011, 02:42 PMNrt
Well, i came across some equations in thermodynamics that was solved with this method it seemed eaiser and faster but i couldnt figure it out on my own. they actually showed us about it in calculus ii last year but i didnt pay much attention since i didnt need it untill now. theres no particular polynominal, feel free to give a simple example.

thanks. - January 16th 2011, 03:21 PMpickslides
Well as you studied calculus I would suggest using newton's method. It is an iterative process.

You keep calculating the next value until you see convergence. This value will be the solution.

For the polynomial choose a starting value in the neighbourhood of the solution, in this case and apply

First find

What did you get?

__Spoiler__:

Note this value and find repeat - January 16th 2011, 03:26 PMNrt
Thank you.