Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

Good morning.


I've this funny problem with maple11. I get an expression as output from a calculus, and I try to simplify it with simplify(%), but simplify don't simplify and give the same expression as result.

On the other hand, If I copy the expression and paste it as argument of simplify it work fine.

Anyone know why this happens?


Thank you


ps: the expression to simplify (in fact is more simple than a simplification: there are terms equals but with different sign to cancel togheter) is



I seem to be running into problems with too much memory use during a large loop leading to maple stopping due to "loss of kernel connectivity".


At the moment I am "resolving" this by saving the variables that I need to continue with the run. Closing down maple manually and opening it again then restarting the loop from the index where I left off. Restarting resets the memory and I can run the code for another 1000 loops or so until I have to repeat the process.


If we consider the finite double sum I:=\sum{r=0}^{i}\sum{r=0}^{j}\frac{(-1)^k(i+j-r-s)! (\mu+\frac{1}{2})_{i+j-r-s}}{r!s!(i-r)!(j-s)!(k-r-s)!(\mu+\frac{1}{2})_{i-r}(\mu+\frac{1}{2})_{j-s}} where j positive integer j positive integer k positive integer such that 0\leq k\leq min(2i,2j) \mu a positive real Question: How we can use maple to justify that I is nonegative Thank you

Element(U,atomicweight) returns a mass, okay but then I choose

Element(Pu,atomicweight) does not return a mass like U but mentions it's a radioactive element and the closest is 244

Is that just the way Maple looks at radioactive elements? 

I recently installed the Student Version of Maple 12 on my Intel Mac OSX 10.5.3 and started to work through the Getting Started Guide. All went well until Section 1.7 Step 7: To plot the expression: 7. Right-click the expression and select Plots → 2-D Plot. On selecting Plots → 2-D Plot, only the arrow was displayed but no plot 2x - 9 → I tried many other methods to obtain plots without success. Using Plot Builder, Preview always produced a plot but Plot always only produced the →. Please advise what I might be doing wrong. Regards, Roger
Hi All, 

I am working on a numerical simulation of a system of ODEs that blows up when I do a numerical solution. One of my advisors says to multiply  the ODEs in my system by -1 to reverse the role of the eigen values. I only vaguely understand this. Would you be able to point me in the right direction to figure this out? When I do this (-1 in front of two of the ODEs), my results are much more stable. I will attach the ODE system here. The parameter values follow.

 Thanks for any input,


 > Restart;

How can one avoid getting a > at the beginning of each line when pasting in several lines of Maple code taken from some other word processor?  I am sure this has been answered many times, but I cannot find the answer now.

Why can I only get the solution  -(-y + 2 x) ^3  (y + 2 x)  from 2) and not from 1).

I am doing the same thing in both of them but from 1) I get "Warning, solutions may have been lost" when Itry to solve for _F1

I want to go from A-B-C with commands (as in 1) ) without having to retype the expression


Hi all,

In Maple, I am integrating a function involving the "erfc" function,

the final integral result has no explicit form, but should be able to
representted as a "\Phi(.)" function, where the "\Phi(.)" is the Gaussian
distribution function (cumulative).

Is there a way to force the following integral to output in the form of
"\Phi(.)" in Maple?


I'm attempting to find where the two peaks are given the following expression.

g(x,y):=(3 x^(2)*y^(2)+4 x^(2)*y+21 x^(2)-4 x*y^(2)-72 x*y-128 x+21 y^(2)+128 y+297)/((x^(2)+2 x+2) (y^(2)-2 y+2) (x^(2)-8 x+17) (y^(2)+8 y-17)):

There are two peaks found by viewing the graph of the expression above.  I've tried using the second derivative test, fsolve with no success. 

This is the command for fsolve i'm trying to use:

fsolve({(D[2](g))(x, y), (D[1](g))(x, y)},{x = -1.5 .. -.5, y = 1.7 .. 1.8})


J'ai une erreur lorsque j'essaie de résoudre un système d'équation différentielle : "Error, (in DEtools/convertsys) unable to convert to an explicit first-order system" et lorsque je simplifie le système j'ai une erreur : "Error, (in dsolve/numeric/DAE/checkconstraints) the initial conditions do not satisfy the algebraic constraints".

Merci d'avance pour votre aide


During a longish run (memory usage gets to about 1815M in 583s ) the loop terminates with the error message

" Kernel connection lost

Hi everybody,

I've got a numerically computed 2D free energy profile given by a set of 3D points (x_n,y_n,E(x_n,y_n)). I'd like to obtain a fit to those points given by some sufficiently smooth analytical function E(x,y) and subsequently compute the critical points (i.e. local minima, maxima and saddle points). Does anyone know if there is any specific package to do this in Maple 8 (or higher) or else what is the best strategy to do so? Thanks in advance.

Dear  Maple World members,


I have a problem and I do not know how to solve this equation with Maple. If anyone can help me, that will a huge gift for me :)

{ [ dy/d(t) ]  / [ dx/d(t) ] } = e*[  ( a + b* y(t) + c* x(t) + d* x(t)* y(t)+ f *y(t)^2 )  / ( a + b*x(t) + c*y(t) + d* x(t)*y(t) + f* x(t)^2 ) ]

initial conditions :

at   t = 0,   x(0) = Xo, y(0) = Yo


Hi, i have the following equation system, for which i  already know the solution.


(-1/(20000*c1)-1/(20000*c2))^2) = 611.0987791:

1/(40000*c2))/((r1+r2)^2+(-1/(40000*c1)-1/(40000*c2))^2) = -8334.070796:

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