# Items tagged with polynomialpolynomial Tagged Items Feed

### Coefficients of differential polynomial...

November 27 2015
1 0

Hello everyone,

I am trying to extract the coefficients from a differential poynomial. In general, this poynomial is in two variables, say u and v along with their differentials, i.e D(u) or D@@2(u) or so on.

Coefficients of this polynomials are rational funcitons.

For instance- consider the following example:

a(x)*v*u+v*D(u)-D(v)*u

then output should be [a(x), 1, -1].

### How to write it through Nu?...

November 26 2015
0 9

Polynomial.mw

Hi all,

I want to rewrite the equation which is attached for you in order to have it in term of Nu. I want to write it such as below:

`()*Nu^7+ ()*Nu^6+... +()*Nu+1=0`

In the above equation the parameters in the parenthesis are function of k1&k2

### Alexander polynomial and knot diagram from Dowker ...

November 20 2015
3
3

Here's a simple package for drawing knot diagrams and computing the Alexander polynomial. A typical usage case for the AlexanderPolynomial function is when a knot needs to be identified and only a visual representation of the knot is available. Then it's trivial to write down the Dowker sequence by hand and then the sequence can be used as an input for this package. The KnotDiagram function also takes the Dowker sequence as an input.

TorusKnot(p, q) and PretzelKnot(p, q, r) are accepted as an input as well and can also be passed to the DowkerNotation function.

The algorithm is fairly simple, it works as follows: represent each double point as a quadrilateral (two 'in' vertices and two 'out' vertices); connect the quads according to the Dowker specification; draw the result as a planar graph; erase the sides of each quad and draw its diagonals instead. This draws the intersections corresponding to the double points and guarantees that there are no other intersections. The knot polynomial is then computed from the diagram.

The diagrams work fairly well for pretzel knots, but for certain knots they can be difficult to read because some of the quads around the double points can become too small or too skewed. Also, the code doesn't check that the generated quadrilaterals are convex (which is an implicit assumption in the algorithm).

knot.txt

knot.mw

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knot.txt

### GCD of polynomials over finite field...

November 11 2015
0 3

Dear

Hope everything going fine with you. I have question

f := x^11+2*x^9+2*x^8+x^6+x^5+2*x^3+2*x^2+1

g := 2*x^10+x^7+2*x^4+x

if we take gcd of infinite field its answer is x^6+1

and the GCD(3)[x]=Z_3[x] is given by x^9+2x^6+x^3+2

How we find GCD(3)[x] in maple.

With my best regards and sincerely.

### Error when fsolving ...

November 05 2015
1 8

Error, (in fsolve/polynom) Digits cannot exceed 38654705646

I am using fsolve to find numerical approximations to the roots of many fairly large polynomials (degrees up to ~80).  I often get this error message and I'm not sure why.  Is there any workaround?  Any help is much appreciated.

### What do these commands mean on Maple help pages?...

November 03 2015
0 3

I was looking for help on polynomial division using Maple via google. But I am having hard time deciphering this web page on quo command. Is this syntax supposed to work on some Maple version?

I also do not understand how the polynomial and the divisor are "entered" without it being assigned to variables like this. I thought it was the browser, but  I tried both Chrome and Firefox and they both show the same page.

Is the above using some new Maple product? I am using Maple 2015 on windows and I get an errors trying to type the above on my Maple worksheet.

### A question about factoring polynomials, and "type"...

November 02 2015
1 2

Hi,

I'm relatively new to using Maple.

I'm looking for information on how the "factor" function works. I printed its definition, and it refers to "factor/factor" and I can't find any more information on this. I'd like to know so that I could have more trust that it works correctly. Specifically, I'd like to be able to believe that if it does not factor a cubic, then the cubic is irreducible.

I'm specifically looking for rational roots of cubic polynomials. The "solve" function seems to work, and gives me the roots in terms of square roots, cubic roots and rationals. I have no idea why I should believe that "type(x,rational)" would work when the description of "x" is quite complicated.

Does anyone know anything about how "factor" works, or how "type" works when testing whether an expression evaluates to a rational number? Any information would be much appreciated.

Thanks,
Matt

### Complex solution...

October 30 2015
1 5

This may be a trivial question, but does this factor fully with the newer versions of Maple, say at 900 digits?

Digits:=900;

rho_poly := -2201506283520*rho^32+(-17612050268160+104204630753280*I)*rho^31+(2237195146493952+737798139150336*I)*rho^30+(14065203494780928-29153528496783360*I)*rho^29+(-260893325886750720-161432056834818048*I)*rho^28+(-1240991775275876352+1727517243589263360*I)*rho^27+(8952004373272068096+6696323263091441664*I)*rho^26+(25553042370906292224-37948239682297921536*I)*rho^25+(-135024511500569280512-65293199430849134592*I)*rho^24+(-79740262928225402880+401487130320847241216*I)*rho^23+(956745211126674882560-164797793704574713856*I)*rho^22+(-1213375867282228772864-1655554058430246551552*I)*rho^21+(-1483956336776821211136+3604946201834409820160*I)*rho^20+(6525094787202650144768-1597915397190007586816*I)*rho^19+(-8575469412912592879616-6168391294117580865536*I)*rho^18+(2408139380338842796032+15004449784317106323456*I)*rho^17+(10583091471310114717696-17047513330720373194752*I)*rho^16+(-22619716982813548707840+8898637295768494915584*I)*rho^15+(26538067620972845277184+5129530051326543351808*I)*rho^14+(-21415800164460070789120-17268159356969925234688*I)*rho^13+(11916012071577094946816+22601135173030541677568*I)*rho^12+(-3551246770922037813248-21229478915196610975744*I)*rho^11+(-977434486760953073664+16249214903618313346048*I)*rho^10+(1977414870691507931136-10721551032564274826240*I)*rho^9+(-1197394212949208115968+6172794574205050632192*I)*rho^8+(280273257275327368320-2996290081120136529792*I)*rho^7+(108849195761508531648+1152454823926345101504*I)*rho^6+(-119736267114490955904-327757949185254534784*I)*rho^5+(49149411853848597568+63563541902968683712*I)*rho^4+(-11524495997215059744-7307364351434838944*I)*rho^3+(1585189353379709888+299568910286253408*I)*rho^2+(-116032795768295808+25487628220230528*I)*rho+3299863116538269-2454681763039104*I;;

### Cannot show the ideal map...

October 20 2015
0 0

with(RegularChains);
with(ConstructibleSetTools);
source1 := PolynomialRing([a, b, c, d]);
target1 := PolynomialRing([e1, e2, e3, e4]);
source1list := [eq2a, eq3a, eq4a, 0];
target1list := [eq2b, eq3b, eq4b, eq5b];
cs := PolynomialMapPreimage(target1list, source1list, source1, target1)

return
cs := constructible_set

then i type
Elements(constructible_set)

it return

Elements(constructible_set)

since source has less number of variables, in order to use this function

i add a dummy variable d to this and use 0 for the fourth equation

### How to enlarge number of variables?...

October 20 2015
0 0

1.

with(RegularChains):
with(ConstructibleSetTools):
source1 := PolynomialRing([a,b,c]);
target1 := PolynomialRing([e1,e2,e3,e4]);
source1list := [eq2a, eq3a,eq4a];
target1list := [eq2b, eq3b, eq4b,eq5b];
cs := PolynomialMapPreimage(target1list, source1list, source1, target1);

Error, (in RegularChains:-ConstructibleSetTools:-PolynomialMapPreimage) number of map functions is different from number of variables in target space

in maple 15 do not have error, however now it has error for the code below

with(RegularChains): with(RegularChains): with(ConstructibleSetTools):

source1 := PolynomialRing([e1, e2, e3]);
target1 := PolynomialRing([a, b, c]);
source1list := [-1*e1+2*e2+*e3, -1*e1+2*e2+*e3, -1*e1+2*e2+*e3];
target1list := [.....]; cs :=
PolynomialMapPreimage(target1list, source1list, source1, target1);

Error, invalid product/quotient

### Bisection method, roots, polynom...

October 19 2015
0 0

Dear all,

I need you help to finish some steps of this idea to approximate the roots of a given equation (polynom). Thanks in advance for your help.

I have a sturm sequence, I would like to use Bisection method to approximation the roots using Sturm decomposition of my polynom. For example, my polynom is  P=x^6-4*x^3+x-2

s := sturmseq(x^6-4*x^3+x-2,x);

sturm(s,x,-2,2); # The number of roots in the interval (-2,2)

Here, i would like to find the roots in (-M,M) :

Bounding all roots in [-M,M] where M = max{1, sum^(n-1) |ai|/an}.

f0 = f, f1 = f', then use -remainder,

I know that  sturm(s,x,-M,M); gives the number of roots in (-M,M)  but is it possible to use the variation of sign like :

gives a Sturm sequence for f.

variation of sign, varsign(a0,a1,...,ar).

Thm: (Sturm) varsign(f0(alpha),...,fr(alpha)) - varsign(f0(beta),..., fr(beta))

is the number of distinct roots of f in [alpha,beta].

then i would like Isolating roots of rational polynomials

Method: reduce, remove rational roots, divide and conquer in [-M,M],

then use bisection  in disjoint closed intervals ctg one root each

Bisection method :

`Bisection`
`      Setup: f(a) < 0, f(b) > 0 (or conversely).`
`      Repeated subdivision of [a,b] guaranteed to get close to a root.`

Error analysis: for error eps, solve (b-a)/ 2^(n+1)  < tol for n. where tol is the tolerance

Thanks

### How to compute radical of polynomial? ...

October 19 2015
0 30

Which of Maple commands is better for computing the radical of a polynomial f (less time of computation and less complexity)?

For example if f=x^3+3x^2y+3xy^2+y^3 then rad(f)=x+y.

### How to deduce that f<>0 w.r.t. B?...

October 18 2015
0 13

Let B is a list of polynomial conditions such that  are none zero. Consider one polynomial f. How can I detect that f is none zero w.r.t. B? For example if B=[a-1,b+2,b-c,ac-1] and f=a^2c-ac-a+1. From B we can conclude that a<>1 and b<>2 and b<>c and ac<>1. How can I deduce that f<>0 w.r.t. B automatically?

October 11 2015
0 3

Hi, I am trying to find adomian's polynomial of exp(y), but after execution it shows DF(e^y), D^2F(e^y) as it is. why it does'nt show its derivative?plz help meNewADP.2.mw

### Plot of p stability region...

October 11 2015
0 7

How can I plot the p stability region in H1and H2 region I already gotten the polynomial

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