MaplePrimes Questions


I am struggling to find a way to change a term like x to x(t) automatically. If I have something like

Data := x^2

diff(Data, x);

the result is 2x

How can I change this 2x to be 2x(t)?





Hi guys,

I am trying to find x(t) from these two equations:

odeA := m*diff(x(t), t, t) = -m*A*sin(2*Pi*f*t) - k*x(t) + 0.5*q(t)*(N__f*epsilon__0*L*(-2*x(t)/(G^2 - x(t)^2) + 2*(G__1^2 - x(t)^2)*x(t)/(G^2 - x(t)^2)^2)*(G^2 - x(t)^2)/(2*tan(alpha)*(G__1^2 - x(t)^2)) + N__f*epsilon__0*L*(-2*x(t)/(G^2 - x(t)^2) + 2*(G__2^2 - x(t)^2)*x(t)/(G^2 - x(t)^2)^2)*(G^2 - x(t)^2)/(2*tan(alpha)*(G__2^2 - x(t)^2)))/(N__f*epsilon__0*L*ln((G__1^2 - x(t)^2)/(G^2 - x(t)^2))/(2*tan(alpha)) + N__f*epsilon__0*L*ln((G__2^2 - x(t)^2)/(G^2 - x(t)^2))/(2*tan(alpha)) + C__p) - d*diff(x(t), t);

diff(q(t), t) = (q(t)/(N__f*epsilon__0*L*ln((G__1^2 - x(t)^2)/(G^2 - x(t)^2))/(2*tan(alpha)) + N__f*epsilon__0*L*ln((G__2^2 - x(t)^2)/(G^2 - x(t)^2))/(2*tan(alpha)) + C__p) + V__bias)/R1


How can I use dsolve to find x(t), apart from q(t) all other parameters are constant.




Can one hope that next version of Maple will be able to solve the standard convection-diffusion pde in 1D?


in 1D. Even the most simple form with zero boundary conditions can't be solved.

sol:=pdsolve([pde,ic,bc],u(x,t)) assuming d>0,c>0,L>0

              sol := NULL

I tried some HINT's also but not all of them.

FYI, Mathematica 12.1 is now able to solve the above PDE



Is it possible I am overlooking some other option or a trick to obtain solution for the above using pdsolve? Only reason I am asking is that Maple can solve much more complicated PDE's and the above is one of the basic diffusion based PDE's. So I am surprised why Maple still can't solve this as it is just a seperation of variables method.

Maple 2020 on windows 10. Physics version 631

Why is my figure not smooth? How can I make it smooth?

with(plots, implicitplot); with(plots)

pp1 := implicitplot(mu*x-ln(1+x) = 0, mu = -10 .. 5, x = -5 .. 5, color = black)





 I have a problem about extremal function.

The function is shown below with restricted condition of x and a:  x>=2 and -1 < a <0.


I guess that  it's minimum value is greater than 0.  In other words,  I want prove that  (x-3/2)^a-(x-1)^a+(1-2^(a-1))*((x-3/2)^a-(x-1/2)^a)-x*((x-3/2)^a+x^a-(x-1/2)^a-(x-1)^a)>0

when I use Minimize function,

Optimization:-Minimize((x-3/2)^a-(x-1)^a+(1-2^(a-1))*((x-3/2)^a-(x-1/2)^a)-x*((x-3/2)^a+x^a-(x-1/2)^a-(x-1)^a),{x>=2, -1<a, a<0})

I 'm not seeing but Error, (in Optimization:-NLPSolve) strict inequalities are not valid constraints. I cannot but add the condition of equality of a : -1<=a, a<=0.

Optimization:-Minimize((x-3/2)^a-(x-1)^a+(1-2^(a-1))*((x-3/2)^a-(x-1/2)^a)-x*((x-3/2)^a+x^a-(x-1/2)^a-(x-1)^a),{x>=2, -1<=a, a<=0})

A result is returned with a warning:
Warning, no iterations performed as initial point satisfies first-order conditions
[0.000000, [a = -2.225074*10^(-308), x = 2.000000]]


Local or Global ?

When I read recent question post

 I'm worrying  that Maple only returns local  extremun. So I use the freely  maple package DirectSearch. We can get it from

DirectSearch:-GlobalOptima(-((x-3/2)^a-(x-1)^a+(1-2^(a-1))*((x-3/2)^a-(x-1/2)^a)-x*((x-3/2)^a+x^a-(x-1/2)^a-(x-1)^a)),{x>=2, -1<a, a<0},maximize);

 Note: I add a  minus sign to find maximize value .

It returns: [0.002264, [a = -0.000203, x = 1.019590*10^13], 605]

But I substitute the value of a and x  into the function,it returns strange result:   4078.360000 not  -0.002264.

I’m confused.. 

I try to use  Mathematica, 

NMinimize[{(x - 3/2)^a - (x - 1)^
    a + (1 - 2^(a - 1))*((x - 3/2)^a - (x - 1/2)^a) - 
   x*((x - 3/2)^a + x^a - (x - 1/2)^a - (x - 1)^a), 
  x >= 2 && a > -1 && a <= 0}, {x, a}]

It retruns {0., {x -> 13.256, a -> 0.}}  May be well.


i need to create a table with information from plots like how many times x become 0

this is the way to make an null oscillation 

please help!

I am trying to calculate the following integra   

here g1 is a kummerM functin in s, and also h1 is another kummerM function  in ss, and f1 and fh1 are the HeunB functions with complex arguments in r and rr. and t=sqrt((r-rr)^2+(s-ss)^2).I would like to integte over dr drr ds dss

restart; F := rsolve({16*s(n+1) = 2+12*s(n)-2*s(n-1), s(1) = 1, s(2) = 5/8}, s); Error, (in s) cannot determine if this expression is true or false: n
solve({sigma*E-(mu+alpha+gamma)*I = 0, gamma*E+Lambda*N*P-(mu+alpha)*R = 0, Beta__1*S*E+Beta__2*S*I/(I*M+1)-(mu+sigma)*E = 0, Lambda(1-p)*N-mu*S-Beta__1*S*E-Beta__2*S*I/(I*M+1) = 0}, {E, I, R, S}, explicit)

I'm not sure if there's something on the page I'm not seeing but even


Maximize(2*x^2 + 2*y^2 + y, {2*x + y <= 6, y^2 - x <= 2})

a literal copy-paste of the posted example maple just repeats what I posted Idk whats wrong. btw is there some way to read the maple documentation pages?


I have some huge troubble with making sure all formula's wont be forgotten by Maple.

For example:

f(x):=f(x);  --> gives me f(x):=f(x) instead of saying f(x):=7

In my document the naming is a bit more complex.

I have a variable named "M_Inwendig2[y]" in the uploaded document. When i name it "M_Inwendig2(y)" (notice [-->( )
maple refuses to use the previous filled/calculated variables.

Due to this error i have copy and pasted the answer to a new formula to continue my work, therefor it becomes quite messy... Now i am trying to fix this.

Ideal all names will be M[inwendig2](y). So the first letter will tell the kind of variable (Moment) the subscript will tell the part (inside) and the depending variable will be between ().

In the document i have marked all error's and copy's RED.

Anyone can advice me? i have named variables the same way in the past, but now it doesnt work.


I had difficulty in making my latest post.  It would fail at Submit.

I had success when I saved a draft post.  I was able to edit the draft to submit.




I am interested in how easy it is to work with formulae in the Maple language.  For example, you can easily add two equations together with '+'.



x^2+1 = 2*x



x^3+x = 5



x^3+x^2+x+1 = 2*x+5



I was pleased when the following example added (x+1) to both sides of an equation,






x^2+x+2 = 3*x+1


Some other algebraic operations work.


x^2-x = x-1



(x+1)*(x^2+1) = 2*(x+1)*x



(x^2+1)/(x+1) = 2*x/(x+1)



(x^2+1)^(1/2) = 2^(1/2)*x^(1/2)



Build-in functions do not work, though, but there is a simple solution.


Error, invalid input: exp expects its 1st argument, x, to be of type algebraic, but received x^2+1 = 2*x



exp(2*x) = exp(x^2+1)



exp(x^2+1) = exp(2*x)



The methods also apply to inequality formulae.  I'm not as pleased about how it does '*' and '/' for inequalities.  You can get more control using rhs and lhs functions.  Here are some examples:  


x^3 < 5*x+5



x^3+x < 6*x+5



x^3-x < 4*x+5



(x^3 < 5*x+5)*(x+1)



(x^3 < 5*x+5)*(1/(x+1))



64/5 < 5






((x^3 < 5*x+5)*(1/(x+1)))/x^2



((x^3 < 5*x+5)*(1/(x+1)))/x^2


lhs(e4)/e3/x^2 < rhs(e4)/e3/x^2;

x/(x+1) < (5*x+5)/((x+1)*x^2)



x/(x+1) < 5/x^2





Any  idea is good for me !


According to Wikipedia ,

Outerplanar graph  is a graph that can be drawn without crossings in the plane (means it is planar graph) with all vertices on the outer face.  

For example 


Recently  in my project, I  need to judge whether a planar graph is a  outerplanar graph.

I tried to find some algorithms but failed. 

Maple  only considers how to test wheather a graph is  planar.

like following:

K4 := CompleteGraph(4)
IsPlanar(K4, 'F')

   Dear friends,on the left I created two Tasks named a and aa.However,I do not know how to delete these two Tasks.Then I refer to the help pages below.

The text I marked says I should enter full filename.I do not know the fullfile name of customized Tasks.So does anyone know how to delete them?


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