## Can someone help me open this file?...

So I have this Maple document that I worked on yesterday, and now when I open it it just opens as the start-up screen where I can choose between document and worksheet mode. I can see that the file is much larger (900 kb) than an empty document, so it should definitely have the data still in there, but opening it with a text editor I couldn't manage to fix my issue. Does anyone have any tips? I have a back-up of the file (from the restore backup menu), but most of the content is not there, so it would be very helpful to get this one fixed.

Exercises.mw
Kristian.

## How to solve non- linear differential equation nu...

Hi everyone, I am looking for help, regarding the solution of nonlinear ordinary differential equations numerically. I have explained my problem in my Maple worksheet. Could anyone please help me in this regard?

Help.mw

## temporal term disappears from the denominator...

Since the temporal term disappears from the denominator for any values of the parameters, I am puzzled. Why is this happening? It seems I might be missing something. When I consider one of the terms (named 'opnumeric') in the denominator and assign parametric values, the temporal term is present. However, when looking at the whole expression, the temporal term is absent in the denominator (named 'den1numeric'). How can this be resolved? numericden.mw

## Explore a surface...

Dear all,

I'd like to explore graphically a polynomial surface depending on two parameters a and b.

The problem is that, as soon as I start playing with the sliders, Maple freezes and I have to 'force quit'.

Can you please tell me if you have the same problem with this example?

Thanks.

 > restart:
 > with(plots):
 > K := 1 - y*x - (1 - x)*(b*x^3 + a*x^2 + x + 1)*(1 - y)*(b*y^3 + a*y^2 + y + 1)
 (1)
 > Explore(plot3d(K, x=0..1, y=0..1,  font= [Times, bold, 20], labels= ['x', 'y','z'],   labelfont= [Times, bold, 40],  title = "K(x,y)"), b = 0..1., a=0..1.);

## non-linear system...

I have this problem with this system of equations, when I solve the 13x13 system it does not give me any solution, neither giving seed values ​​nor placing full digits. The exercise is solved and I tried to assume close values ​​and it doesn't work for me, it leaves everything expressed with the fsolve command.

## How does Maple solve, int(y'(x)*f(x), x) =[int(sqr...

'odeadvisor' suggests isolating y(x) from the equation as a first step, y=G(x,y'(x)), then apply the method of 'patterns'. For the first step, y(x) = (9/4)*[(y'(x))^2]/{[int(f(x),x)]^5} is what I found but, could take it no further. Nevertheless, Maple finds an intrinsic solution of the form, (3/4)*y(x)^(4/3) +(2/3)*int(sqrt(y(x)*f(x))^(-5/3) + _C1 =0, from which an explicit solution can be obtained. If anyone can supply the steps leading to the Maple solution - that would be great.

## How do I solve a system of differential equations ...

Hello everyone

I need help solving a system of equations as below. I'm looking for a way to do it, but I don't understand the general concept of how such an equation is calculated. So far I've been using a package in LabVIEW that worked similarly to Simulink and that was clear to me, whereas here I'm overwhelmed by the multitude of options and that's why I'm asking for help.

I need to solve these equations analogously to Matlab-Simulink, i.e., a time interval and integration step, and a numerical procedure in symbolic versions.

Help_me.mw

## Multiplaction "dot" is way too small - causes erro...

Multiplaction "dot" in Maple 2022 is way too small - causes errors.

e.g. two variables multiplied s*m ends up being sm a new variable as I cannot really see that there is a missing multiplication operator between the variables. This causes huge unnecessary errors.

Maple 9.x e.g had nice clear and big operators and this kind of error was avoided.

How can I undo this unfortunate regression in Maple 2022 to increase the size of multiplication operator and other operators, so that they actually becom visible and not just a little dot almost a pixel in size.

If I was a falcon (20x20)^infinity then this would have been ok, but I am not, I am human.

So how do I change this unfortunate regression so that these errors can be avoided.?

## integration in if-statement...

How can I get the evaluation of integration inside if-statement?

 > restart;
 > #L:=1:sigma:=0.01:beta:=0.2:k0:=-100:
 > #For Free particle Projectile := proc({L:=1,sigma:=0.01,beta:=0.2,k0:=-100},n_max) local x0,g,c:  x0:= beta*L;  g := unapply(exp(-(x-x0)^2/2/sigma^2),x);  #c := int(g(x)^2,x=-L/2..L/2,numeric=true);  ub := (L/2-x0)/sqrt(2)/sigma;  lb := (-L/2-x0)/sqrt(2)/sigma;  a := Pi*sqrt(2)*sigma/L;  b := sqrt(2)*k0*sigma;  c := Pi*x/L;  d := k0*x0;  eq1 := [cos(a*n*z)*cos(b*z)/e^(z^2),cos(a*n*z)*sin(b*z)/e^(z^2),sin(a*n*z)*cos(b*z)/e^(z^2),sin(a*n*z)*sin(b*z)/e^(z^2)];  eq1 := map(f->unapply(f,n,z),eq1);  eq2 := [cos(n*c)*cos(d),cos(n*c)*sin(d),sin(n*c)*cos(d),sin(n*c)*sin(d)];  eq2 := map(f->unapply(f,n,z),eq2);  for j from 1 to n_max do:    if (is(j,odd)) then eq11 := int(eq1[1](j,z),z=lb..ub,numeric=true);    else 0;    end if;  end do: end proc:
 >
 > Projectile(1);
 (1)
 >

## strange window behavior problem...

OS Linux

I have Maple 2022 open with a worksheet on a specific workspace.

I then move to a different workspace and want to start a new instance of maple for a new problem.

In command line I exacute

\$]xmaple22 –standalone  filename.mw

Unfortunately when the new instance is started, the open maple instance on the first workspace is moved automatically to the second workspace together with the new instance opened, completely messing up the organization.

This is not expected behavior.

How can I make Maple execute absolutely independent instances of xmaple22 without indiscressionately and automatically moving existing open maple instances to the current workspace.

Severely annoying. Maple 9.5 e.g. does not have this behavior at all so Maple 2022 is a step backwards in this regard.

Thanks

## HELP WITH A CORRUPTED FILE ASAP!...

Hey! I need help ASAP, because my maple file has been corrupted and i dont know what to do. Do you guys know how to recover a file? i can save it again as_mw. but should i change it to xml? or how? i have the link to my maple file attached, so if someone can help me, it could be helpful! Because i have an upcoming exam. Thanks youu

## How to compute right eigen vector of a matrix in ...

How to evaluate the right eigenvector of a given matrix in maple?

## how to plot impulse points in the differential equ...

For t not equal to nT,

dS/dt = delta- mu*S+ omega*V;

dV/dt = -(omega+mu)*V

For t=nT,

S(nT+)=(1-gamma) S(nT);

V(nT+)=V(nT)+ gamma* S(nT),

with the initial conditions  S(0+)=s0

V(0+)=v0

how to plot the graph with this system of equations,impulsive points and initial conditions

## how do I solve and plot fractional differential eq...

I want a maple code to solve the caputo fabrizio differential equations using Runge Kutta method with implicit functions and impulsive conditions in maple. Is there any code structure for that.

## is this correct to solve the implicit fractional d...

restart;
with(Student[NumericalAnalysis]);
with(plots);
with(DEtools);
f := proc(u, r) local res; res := 1/25*r^2 + (sin(u(r)) + sin(diff(u(r), [r \$ 1/5])))/(r^2 + 47); return res; end proc;

RK4 := proc(f, u0, r0, h, n) local u, r, i, k1, k2, k3, k4; u := Vector(n + 1); r := Vector(n + 1); u[1] := u0; r[1] := r0; for i to n do k1 := f(u[i], t[i]); k2 := f(u[i] + 1/2*h*k1, r[i] + 1/2*h); k3 := f(u[i] + 1/2*h*k2, r[i] + 1/2*h); k4 := f(u[i] + h*k3, r[i] + h); u[i + 1] := u[i] + 1/6*h*(k1 + 2*k2 + 2*k3 + k4); r[i + 1] := r[i] + h; end do; return [u, r]; end proc;
RK4 := proc (f, u0, r0, h, n) local u, r, i, k1, k2, k3, k4; u

:= Vector(n+1); r := Vector(n+1); u[1] := u0; r[1] := r0;

for i to n do k1 := f(u[i], t[i]); k2 := f(u[i]+(1/2)*h*k1,

r[i]+(1/2)*h); k3 := f(u[i]+(1/2)*h*k2, r[i]+(1/2)*h); k4 :=

f(u[i]+h*k3, r[i]+h); u[i+1] := u[i]+(1/6)*h*(k1+2*k2+2*k3+k4\

); r[i+1] := r[i]+h end do; return [u, r] end proc

u0 := cos(abs(0.9))/15;
u0 := 0.04144066455

r0 := 0;
r0 := 0

h := 0.1;
h := 0.1

n := 100;
n := 100

solution := RK4(f, u0, r0, h, n)

u := solution[1];
r := solution[2];
plot(u, r, style = line, color = blue, labels = ["Time (r)", "Solution (u)"]);
is this correct to solve the implicit fractional differential equations using 4th order Runge-Kutta Method. will fsolve command  solve the fractional differential equations ?

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