Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

If I used factor, it didn't simplify to 0. As you may notice that this value should be 0.

Hello,

every time I input a formula I get:

Typesetting:-mparsed(x^2 +5 -2,x^2+3; "_noterminate")

I can't get rid of this error: this is very basic, what happened?

TIA, Roberto

 

I think   looks much nicer than

it is indeed the answer to .  Both above are equal but there are less terms on the left.  It's just what Maple does - it doesn't like radicals in the denominator.  For just a little overhead I would prefer a collection of any sqrt value into the denominator than to have to split it up.  Maybe just my preference.  Perhaps an option could be available within the Maple system to allow numeric radicals in the denominator? 


I get the following errors when attempting to use the Sockets package to interface with the serial input and output for a USB device connected and reported to have no known problems by Windows 10:

with(Sockets):
LookupService("busboy");
Error, could not determine determine port number for service "busboy"

LookupService(998);

Errror, cannot  determine "tcp"  service on port 998




server :=
proc (sid)
Sockets:-Write(sid, sprintf("Hello %s on port %d, from %s\r\n", Sockets:-GetPeerHost(sid), Sockets:-GetPeerPort(sid), Sockets:-GetHostName()))
end proc;

Sockets:-Serve(GetPeerPort(sid), server);
 
Error, (in Sockets:-GetPeerHost) Unknown error

sid := Open("localhost", "echo");

Sockets:-Serve(GetPeerPort(sid), server);

Error, (in Sockets:-Serve) cannot bind address: Unknown error
 

How can we solve the following pde by Maple? 

where v is velocity, v with dot is acceleration. (So, I think we will assume that acceleration is fixed.) And \delta is Dirac distribution.  E,I,m, M , g are fixed numbers.

Boundary conditions are:

Initial conditions are:

 

You can find the equation in the code: question.mw

Hi

I have a problem with my maple. 

 

corrupt file 

Is there anybody who can help me solve this problem. 

Casper 

i want to gain diff(p(t), t) and diff(q(t), t) and Jacobian matrix
 according to the attached pdf file.

please help me.

thanks

simplify.mw
 

k := diff(a(t), t) = -mu*a(t)-(1/4)*alpha6*a(t)*sin(gamma(t))

diff(a(t), t) = -mu*a(t)-(1/4)*alpha6*a(t)*sin(gamma(t))

(1)

j := a(t)*(diff(gamma(t), t)) = 2*a(t)*sigma-(6*(1/8))*(alpha1-alpha2+(1/3)*alpha3)*a(t)^3-(1/2)*alpha6*a(t)*cos(gamma(t))

a(t)*(diff(gamma(t), t)) = 2*a(t)*sigma-(3/4)*(alpha1-alpha2+(1/3)*alpha3)*a(t)^3-(1/2)*alpha6*a(t)*cos(gamma(t))

(2)

"p(t):=a(t)*cos(gamma(t))"

proc (t) options operator, arrow, function_assign; a(t)*cos(gamma(t)) end proc

(3)

"q(t):=a(t)*sin(gamma(t))"

proc (t) options operator, arrow, function_assign; a(t)*sin(gamma(t)) end proc

(4)

diff(p(t), t)

(diff(a(t), t))*cos(gamma(t))-a(t)*(diff(gamma(t), t))*sin(gamma(t))

(5)

(-mu*a(t)-(1/4)*alpha6*a(t)*sin(gamma(t)))*cos(gamma(t))-a(t)*(2*sigma-(6*(1/8))*(alpha1-alpha2+(1/3)*alpha3)*a(t)^2-(1/2)*alpha6*cos(gamma(t)))*sin(gamma(t))

(-mu*a(t)-(1/4)*alpha6*a(t)*sin(gamma(t)))*cos(gamma(t))-a(t)*(2*sigma-(3/4)*(alpha1-alpha2+(1/3)*alpha3)*a(t)^2-(1/2)*alpha6*cos(gamma(t)))*sin(gamma(t))

(6)

diff(p(t), t)

2*t

(7)

``


subs.pdf

Download simplify.mw

 

 

Hi, I'm using Maple 2018 and I tried to run coding from https://www.maplesoft.com/applications/view.aspx?sid=4194&view=html

however, it said : unable to parse. I figured out that the problem maybe is in the if loop. though it seems perfectly fine, but it has some goto commands that i cannot search on maple website. does this mean that the goto cannot be used here and should be replaced? if yes, then how? 

i am still learning on how to use maple. any help would be much appreciated. thank you!

this is the coding for if loop:

 

label_7;

rv:=vector([p1(x1pt,x2pt),p2(x1pt,x2pt)]):

numgeval:=numgeval+1;

printf("%5d (%8.4f,%8.4f)",numIter,rv[1],rv[2]);

max:=n;

mg:=convert(sqrt(dotprod(rv,rv)),float);

printf("%12.4f",mg);

if(mg<tol or numIter>=max) then

goto(label_6);

else

numIter:=numIter+1;

fi;

v1:=x1pt+t*rv[1];

v2:=x2pt+t*rv[2];

newt:=evalf(subs({x1=v1,x2=v2},f1));

numfeval:=numfeval+1;

lam:=fsolve(diff(newt,t)=0,t,maxsols=1);

nv1:=evalf(subs({t=lam},v1));

nv2:=evalf(subs({t=lam},v2));

printf(" (%8.4f,%8.4f)%13.4f\n",x1pt,x2pt,lam);

x1pt:=nv1;

x2pt:=nv2;

goto(label_7);

label_6;

printf("\n\n-----------------------------------------");

printf("---------------------------------------------");

printf("\n\n Approximate Solution: ");

printf(" (%8.4f,%8.4f)\n",x1pt,x2pt);

Fvalue:=evalf(subs(x1=x1pt,x2=x2pt,f));

printf(" Maximum Functional Value: ");

printf("%21.4f",Fvalue);

printf("\n Number gradient evaluations:");

printf("%22d",numgeval);

printf("\n Number function evaluations:");

printf("%22d",numfeval);

printf("\n\n-----------------------------------------");

printf("---------------------------------------------");

end:

Hello, 

I am fairly new to using the Maple software, so I apologize if my question is completely idiotic. Apologies, also, because I could not manage to enter my code as code. When I pressed the button it made the whole text as a code. 

I run the following code to seek -if there are any- analytic solutions for the following differential equation.

odeplus := (r^2+L^2)^(5/2)*(diff(f(r), `$`(r, 2)))+((15/4)*r*(r^2+L^2)^(1/2)+3*(r^2+L^2)^(5/2)/r)*(diff(f(r), r))+M^2*f(r)/(r^2+L^2)^(5/2)-((5/2)*((r^2+L^2)^(1/2))(l-1)+(55/64)*r^2/(r^2+L^2)^(3/2)+(r^2+L^2)^(5/2)*(l^2+3*l+3/2)/r^2)*f(r)+(((r^2+L^2)^(1/2))(5+(5/2)*l)+(5/8)*r^2/(r^2+L^2)^(3/2)-(r^2+L^2)^(5/2)*(3/2+l)/r^2)*f(r) = 0

and then I do 

dsolve(odeplus, f(r))

The solutions that Maple returns is given in terms of DESol. Could anyone try and break it down for me? What is this telling me and if I can indeed from the output obtain analytic solutions? Is this some sort of operator acting on something? 

Thank you in advance. 

Hello ,

Iam new with maple, and iam trying to solve an equation using prime numbers. The equation is display as follow.

eqns := {G = x*q, 8695*y = 1341*q};

Iam trying to solve with the condition p and q are prime numbers

So is it posible to add condition prime in the solve fonction ? solve(eqns*[x, y]); 

Thank you for your help

I hate it when a user bumps every Question that they've ever asked over the past five years to the top of Recent (aka Active Conversations) stack! This is not the first time that this has happened. I rely heavily on that stack being truly the threads with the most-recent material. Can't something be done about this short of deleting the threads? That seems too drastic: While this user has occasionally been a pest in the past, they've also posted some decent material. There should be some way for a moderator to just reset the stack positions to what they were previously.

hi.

According to the fhgure attaceh how i can gain the equation (2-27) . I write the equation (2-26) in maple but I couldnot to gain that result.

If possible to reach equation via maple?

Thanks

diff.mw
 

restart

FC := (1/2)*W_m^2*(c1*x^2+c2*y^2)+(E.(h^2))*W_m^2*(sum(An*((sinh(n*Pi/lambda)+n*Pi*cosh(n*Pi/lambda)/lambda)*cosh(2*n*Pi*y/a)-2*n*Pi*y*sinh(n*Pi/lambda)*sinh(2*n*Pi*y/a)/a)*cos(2*n*Pi*x/a)/(n^2*(sinh(n*Pi/lambda)*cosh(n*Pi/lambda)+n*Pi/lambda))+Bn*((sinh(n*Pi*lambda)+n*Pi*lambda*cosh(n*Pi*lambda))*cosh(2*n*Pi*x/b)-2*n*Pi*x*sinh(n*Pi*lambda)*sinh(2*n*Pi*x/b)/b)*cos(2*n*Pi*y/b)/(lambda^2*n^2*(sinh(n*Pi*lambda)*cosh(n*Pi*lambda)+n*Pi*lambda)), n = 1 .. n))

Warning,  computation interrupted

 

S := diff(FC, x); SS := diff(S, x)

g := subs(x = (1/2)*a, SS)

0

(1)

coeff(g, sinh(n*Pi/lambda))

0

(2)

``


 

Download diff.mw

I tried the example in BodePlot help.

restart;
with(DynamicSystems):
sys := TransferFunction( 1/(s-10) ):
BodePlot(sys);


That works OK. But, if I invoke Syrup, the example no longer works.

restart;
with(Syrup);
with(DynamicSystems):
ckt := [V, Rsrc(50), C1(15e-9), L1(15e-6), C2(22e-9), L2(15e-6), C3(22e-9), L3(15e-6), C4(15e-9), 1, Rload(50)];

TF := subs(other, V=1, v[Rload]);
sys := TransferFunction(TF);

BodePlot(sys);
I get a message "not a valid plot structure".  OK, try the example, again.

sys := TransferFunction( 1/(s-10) ):
BodePlot(sys);
I also get the "not a valid plot structure" message.

What am I doing wrong?

Respected sir,

I have attached a file that contain integration . Sir I am unable to solve please give me some hint.

PLease note followings 

1. I want to get final expression , want to get the value of constant from boundary condition.

2.I want to get the final expression (.......+c1)

3.I will put boundary condition to determine the value of c1

Can somebody please help me with this assignment?
Struggling a bit with the Euler-method from task d) and further.

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