topic Re: How to compute cubic roots using polyroots for continuous values in Mathcad

How to compute cubic roots using polyroots for continuous values

vveeran — Thu, 03 May 2018 14:29:10 GMT

Dear all,Previously, I attached this file but I couldn't explained clearly in the worksheet.Now, I updated the worksheet and explained clearly 'what to do? '.I want to compute cubic roots using polyroots for continuous values (-84.948....20.136) for my example programand

Re: How to compute cubic roots using polyroots for continuous values

Werner_E — Mon, 09 May 2016 02:51:05 GMT

Maybe the attached file helps.

You have to turn the calculations into function depending on Vm (you doen't need "coeff" as you provide the coefficients yourself.

You should use a range variable only for plotting. To calculate a couple of values you shoul use a vector of Vm-values.

Not sure, but you may have to find a solution to cope with Mathcads habit of changing the order of the three roots depending on the real part (at least thats what I think it does) if thats not what you need and want.

Regards

Werner

Re: How to compute cubic roots using polyroots for continuous values

vveeran — Mon, 09 May 2016 04:34:09 GMT

Dear Werner,

Thank you for your valuable comments.

It helped me a lot.