Hello,

I am facing the error message "Error, (in factors) Bad inputs to diophant." raised by a call to

factors(p, {I, sqrt(3)}) 

for a polynomial p in 7 variables (with integer coefficients). Unfortunately, the error is not reproducible: After some thousand calls to factors (with different polynomials) this error suddenly occurs.

1. Interestingly, it does not depend on the actual polynomial,...

I know how to solve system of differential equations numerically, but now I want to know how to set a bound on the solutions. 

For example, if my system of DE is like this:   dx/dt = x+y   dy/dt = x-y    , solve x and y in t. 

I can solve this without any restriction on x and y, now I need to know how to bound x and y, e.g. x can only fall in the interval [0,1]

Thank you very much!

Hi, I am trying to do the calculation with a matrix, and I have hard time to find a way to calculate the Moore-Penrose generalized inverse of a matrix in Maple. Could anybody help me?

I have a solution with RootOF(_Z^6+....). I do not need to find the roots explicitly(I know that I should use 'allvalues' to find the roots). My question is "Is it okay if I use RootOF(...) expression in another equation without finding the roots explicitly? I mean does RootOF(_Z^6+...) stand for all its roots and can it be used for each roots?"

Thank you in advance.

Anybody has a hint on how to solve a non-linear system with trigonometrics. I want to solve x, y and z.

How can I use factor in equations?

For example:

x^6+y*x^4+z*x^2-g*x^4-3*x^6====>-2*x^6+(y-g)*x^4+z*x^2

or

a*cn+w*dn+e*cn+f*dn=====>(a+e)*cn+(w+f)*dn

These examples are very simple.

Thank you

How do you graph y''+8y'-9y=0?

How do you graph 4y"-y=0?

And for these i need to sketh the graph of the solution solution and describe its behavior as t increases.

with Maple?

Hi all,

I must confess I'm a perfect novice in Maple as I'm used to work with Matlab. I have a 3d differential equation, namely:

= 0

The components of M should be of the form M_{i0} + dM_i(t) where M_{i0} is a constant and dM_i(t) a function of t, i = 1, 2, 3. And...

Hi,

I was wondering, suppose I have an ordinary differential equation, y''(x)  + y(x) - y(x)^3, and that the RHS is equal to zero (Duffing type equation).. Is there any way to declare this as in Maple, such as,

y''(x):=y(x)^3-y(x);

so that any time Maple sees y''(x) + y(x)-y(x)^3 in an expression, it will replace it with zero? I have tried the above, but it receive an error which says, "error, illegal use of an object as a name." 

Hi!

I am a mechanical engineer.

I want to differentiate a potential energy functional (a multivariable functional combination of integrals) in the variational calculus to get the Euler-Lagrange equations and boundary conditions and then to solve ODE's and PDE's to get a closed form solution.

The form of PE:=F(x1,x2,x3,w1(x1,x2,x3),w2(x1,x2,x3),w3(x1,x2,x3),diff(w1,x1),etc...)

Interested in getting diff(F,w1)  and diff(F,diff(w1,x1)).

Dear all,

I have to optimize polynomials with 10Mio data.

for i from 1 to ... do v[i]:=Optimization[NLPSolve](g(A[i,1],A[i,2],0.01273,x),x=0..3,method=branchandbound,maximize)[2]od;

This gives the result I wish, but formated like [x=0.] .

I would like to write only the x-values (floats) to a .txt file.

writedata("c:test.txt",v);

gives an error.

I must have the results on Friday, so would be very grateful for a fast answer.

 I want to evaluate the values of x and y and the data should bo saved in .xls format  from contour plot 

for g=0.1 the data x and y values  should be stored in xls sheet 1  atleast 50 values 

similarly  in separate xls sheet 

for g=0.0 the data x and y values  should be stored in xls sheet 1  atleast 50 values 

with(plots):
g:=y*(1-1/(x^2+y^2)):
colors:=table([0.1=blue,0.0=green,0.2=red]):
display(seq(contourplot(g,x=-1..1,y=0..2,
contours=[i],color=colors[i],axes=boxed,legend=(i)),i=[0.1,0.0,0.2]));

thanks in advance

Dear Experts,

I am novice to Maple 14, to do some numerical work I am using its 2D math input. I am having problem while using an itegral equation with a limit from 0 to infinity, when I use this limit; in answer I got un-solved equatoin instead a numerical value and this un-solved equation have FLOAT value, when I tried with some other input that time maple give answer again 

Hi all, 

R_ab▽^a▽^bΦ where R_ab -Ricci tensor, and Φ-Scallar field, and I think derivation is covariant derivative.

How should I contract the indeces of this expression on Mapple?

Please, help me to figure it out. 

Thanks in advance.