Error in computing the polyroots

[vveeran]

Hi all,

I want to compute polyroots for the example program which I attached below.

But, I am getting some error in computing the polyroots.

Please help me to find out roots for my example program.

Also, I need to plot Real and Imaginary part of poles of the

given example program.

[Werner_E]

polyroots is a numeric function bit your coefficients include the LambertW Function which in Mathcad is only known by the symbolics. Thtas the reason for the error.

[vveeran]

Dear Werner,

Could you please correct the error of my program

and find the roots of my given program,

So that it will be helpful to me.

Thanks.

[-MFra-]

I would do so, I do not know if that's what you want

[vveeran]

Dear F.M,

Thank you for your reply.

That is what I needed.

Could you please attach the code.

could you please explain,

why did you initialized like this,

gamma1= gamma1, x=x , beta1=beta1

what is the meaning of this,

ans(v)->LambertW((v^2*beta1/20)v + beta1(v)*gamma1(v)) / beta1(v)

Similarly,

If suppose I have cubic roots like,

a3(v) s^3 + a2(v)s^2 + a1(v)s +a0(v) = 0

where a3(v), a2(v), a1(v) and a0(v) are coefficients.

How to compute the roots by using the above procedure.

[-MFra- · Accepted solution]

I'm sorry! I provide immediately. But also the F. Kolepp solution is of some merit.

About your question:

1) When looking for a symbolic solution, you have to reset all the variables and constants involved. Otherwise you will not get a symbolic result, but a numeric result.

2) That is the symbolic solution of the equation included in the "Given-Find" block.

3) simply replace the quadratic equation with the third degree where there is the symbolic operator "solve".

Bye

[Fred_Kohlhepp]

If you convert v from a range to a vector you can make your sheet work.

See attached.

[vveeran]

Thank you all

for your replies.