Hi, I have the following simple differential equation. 

2x dx -9y^2 dy = 0

How can I enter the command to solve it? I know I'm supposed to use dsolve command, but I keep getting an input error saying that it expected an ODE. Google says that said message is because for whatever reason Maple cannot understand dx or dy, and that instead I need to use diff command. But when I enter: 

2x diff(x) - 9 y^2 diff(y) = 0

I get another error. I have tried other combinations, but at times I get errors like y(x) and y cannot both appear in the given ODE, which I don't understand why they can't as they are like basic run of the mill ODEs, so I'm a bit confused. 

I have also checked Maple's docs but they don't help either, I tried the first example given here: 
https://www.maplesoft.com/support/help/Maple/view.aspx?path=dsolve
 and I got the same "expecting an ODE or a set or list of ODEs" as in my own examples, so I'm guessing the docs are assuming steps or some configuration. 

How am I supposed to enter the command? Thanks in advance!

Hello,

I want to evaluate the change of temperature and energy loss during the flow through an expansion valve.

But the command fsolve this does not work with CoolProp.

The following command is just repeated, but gives no result.

fsolve({ThermophysicalData:-Property("D", "H2", "temperature" = TTT, "pressure" = ppp) = 31.13, ThermophysicalData:-Property("H", "H2", "temperature" = TTT, "pressure" = ppp) = 4.098640000*10^6}, {TTT, ppp})

Regards,

Andreas

Some years ago it was promised that expansion of capabilities of Heun functions was imminent, but nothing has appeared.  Other functions long overdue for inclusion as special functions in Maple are the Lame functions, which arise as special cases of Heun's differential equation and therefore of Heun functions.  Lame's differential equation appears in Abramowitz and Stegun, but has long been neglected in Maple.  These spectial functions are much more generally useful to users of Maple than, for instance, esoteric parts of the physics package. 

Is this documented somewhere?  Why Maple do not return 0 from odetest after expanding the solution?

update: added additional tries to simplify it to zero as suggested but they do not give zero.

Download odetest_q.mw

Hi, I ran the following command: 

int(x^2 * sqrt(1-x^2), x)

and I got a solution. Then I try IntTutor: 

IntTutor(x^2 * sqrt(1-x^2), x)

And a UI window popus, does nothing. When I click "All Steps" it says "Unable to solve this problem". How so, if int() just gave me an answer? Or am I using the commands wrong?

I'm trying to see the steps by step solution of the integral, so I can compare it with my attempts. Kinda like what http://integral-calculator.com/ does. Thanks in advance. 

Hello

As title says, when I enter equation in math mode and switch to text mode and hit "enter" to go to the next line then it gets executed, usually in former versions it didnt execute and was much faster for me to use the program this way.

How do I fix this? I don't want to use shift-F5 all the time to make the text unexecutable, I would like it to be like in the old version prior to 2019.

Now it does this which is really annoying, I dont want it to execute when changing line!

Best regards

Jonas

i literally cant figure out how to pay money for this

I'm using dsolve command to solve a differential equation. Using infolevel to 3 will tell me the classification of said DE. However, how can I see the step by step solution? I'm using Maple as a study tool so I do solve manually a DE then I'd like to compare my answer with Maple's. How can I acomplish this? Thanks in advance. 

Please may I know if you can offer ma student's discount ob the seleted version.

Thank you.

Fred.

I'm a Maple novice.  I have two questions.  (1) I'm trying to use Maple to confirm some Fourier transforms of selected probability density functions.  In general I've succeeded, but Maple fails to find the Fourier transform of the pdf of a logistic random variable with mean 0.  Please explain how I can get Maple to carry out this request.  I've attached a Maple file with my work to this question.  (2) At several points in my computations, I wish to substitute 2*Pi*xi for omega.  I have an expression containing two omegas.  If I use algsubs(), only one of the two omegas is replaced.  I have to use subs() to replace both omegas.  Why is this?
 

Download Logistic_pdf.mw

How do I calculate the intersection curve between a plane and a drop?
The "drop" is defined in the following way:

R1 := 3.;R2 := 1.0;DR := 4;g := R2 + DR;

f1 := h -> sqrt(R1^2 - h^2);
f2 := h -> sqrt(g^2 - h^2);
f3 := h -> (1 - h/g)*f1(h*R1/g) + h*f2(h)/g;
f4 := h -> sqrt(1/2*g - 1/2*h);
f5 := h -> (1 - h/g)*f3(h) + h*f4(h)/g;
gg := h -> piecewise(h < 0, f1(h), 0 <= h, f5(h));#Radius depending on the z-position h
cir := (h, phi, R) -> <sin(phi)*R, cos(phi)*R, h>; # a circle at the hight h with radius R
#The plane is placed inside the drop.
n := (x, y, z) -> <x, y, z>/sqrt(x^2 + y^2 + z^2);

# the following lines show, how it looks like:
with(plots);
with(plottools);
dro1 := plot3d(cir(h, phi, gg(h)), h = -R1 .. g, phi = 0 .. 2*Pi, scaling = constrained, orientation = [-60, 72, 0]);
plotDropWithPlane := (x, y, z) -> display(dro1, arrow(Vector([0, 0, 0]), 2*R1*n(x, y, z), 0.2, 0.4, 0.1, cylindrical_arrow, fringe = blue, color = "Green"), implicitplot3d(x*x1 + y*y1 + z*z1 = 0, x1 = -R1 .. R1, y1 = -R1 .. R1, z1 = -R1 .. g, color = blue));
plotDropWithPlane(3, 1, 2);

#I'm searching a function like
fintersect:=theta-><"?,?,?>"

Any idea how to solve?

Best regards,

Andreas

Download Derivative-numerical.mw

Does anyone know how to enter in the pdsolve function Dirichlet conditions and Neumann values?

Oliveira.

Why Maple returns -1/x as singular solution below when this solution can be obtained from the general solution when constant of integration is zero?

Download essential.mw

I've made this proc and it has 2 outputs




*

How do I fix that?