Hello,

I want to solve three coupled differential equations with initial and boundary conditions numerically and get the plots of solutions.

But I received errors.

Could you please help me to solve the error and get all three plots that I need?

My codes:

restart;

sys := {diff(phi(eta), eta$2) + 5.261282735*f(eta)*diff(phi(eta), eta) - 2.630641368*phi(eta) = 0, 1.059704409*diff(theta(eta), eta$2) + 6.176017503*f(eta)*diff(theta(eta), eta) + 21.03607964*diff(f(eta), eta$2) + 0.5*phi(eta) = 0, diff(f(eta), eta$4) - 1.052256547*diff(f(eta), eta)*diff(f(eta), eta$2) + 1.052256547*f(eta)*diff(f(eta), eta$3) + 5.165076420*diff(theta(eta), eta) + 5.261282735*diff(phi(eta), eta) = 0, eval(diff(phi(eta), eta), {eta = 0}) = 1 + 0.5*eval(diff(f(eta), eta$2), {eta = 0}), eval(diff(phi(eta), eta), {eta = 1}) = 0.5*eval(diff(f(eta), eta$2), {eta = 1}), f(0) = -0.5, f(1) = 0.5, phi(0) = 1, phi(1) = 0, theta(0) = 1, theta(1) = 0};

dsol:=dsolve(sys,numeric);
Error, (in dsolve/numeric/bvp/convertsys) unable to convert to an explicit first-order system
plots[odeplot]((dsol),eta=0..1);
Error, (in plots/odeplot) input is not a valid dsolve/numeric solution

Thank you.

To Maple support,

Why when removing symbol a from these equations makes Maple warning go away? This is from a textbook. Attached worksheet. 

restart;
ode:={diff(x__1(t),t)*sin(x__2(t))=x__4(t)*sin(x__3(t))+x__5(t)*cos(x__3(t)),diff(x__2(t),t)= x__4(t)*cos(x__3(t))-x__5(t)*sin(x__3(t)),diff(x__3(t),t)+diff(x__1(t),t)*cos(x__2(t))= 1,diff(x__4(t),t)-(1-B)*a*x__5(t)= sin(x__2(t))*cos(x__3(t)),diff(x__5(t),t)+(1-B)*a*x__4(t)=sin(x__2(t))*sin(x__3(t))};
dsolve(ode)

restart;
ode:={diff(x__1(t),t)*sin(x__2(t))=x__4(t)*sin(x__3(t))+x__5(t)*cos(x__3(t)),diff(x__2(t),t)= x__4(t)*cos(x__3(t))-x__5(t)*sin(x__3(t)),diff(x__3(t),t)+diff(x__1(t),t)*cos(x__2(t))= 1,diff(x__4(t),t)-(1-B)*x__5(t)= sin(x__2(t))*cos(x__3(t)),diff(x__5(t),t)+(1-B)*a*x__4(t)=sin(x__2(t))*sin(x__3(t))};
dsolve(ode)

worksheet attached also

Download warning_may_10_2022.mw

Hi,

I want to plot a quadric with important elements ( center, Principlal directions, Principal planes..) 

Ideas ? Thanks

Download QuadricQuestion.mw

Anyone keen to spend some time helping me with an error?

I'm getting the error mentioned above with Maple 2022 (but can also be reproduced in 2021).

Originally the error comes from within a company library, but I've managed to reproduce it without the library by merging the library in the workbook.

The error arises during a simple addition / subtraction operation, and I have no clue why.

P.S.: I've also filed a request to Maple support on this one.

CrashTest.zip

Let say, 

A= A1+A2+.....................+An

B=B1+B2+.....................+Bn,

C=C1+C2+.....................+Cn

And all the values of A1 to Cn may be both positive or Negative.

Then, how to program to find the Maximum Value of  (A^2+B^2+C^2+A.B+B.C+C.A)^(1/2).

The long form of ScientificConstants[GetValue] is not working in at least Maple 2021 and Maple 2022

ScientificConstants[GetValue](Constant(g))

This is causing issues for MapleFlow, not being able to call on a constant. 

**edit some of the long forms work - specifically the GetValue does not.  I modified the title to reflect that.**

i have this sequence :f:=n->n/n+1
       

> f1:=seq(f(n), n = 0 .. 10);
                       f1:= 0,1/2,3/4,4/5,5/6,6/7,7/8,8/9,10/11

i want to create these sequences by using f :

1) 0,2/3,4/5,6/7,8/9,...

2)2/3,9/10,16/17,..

3) 1/2^2,3^2/4^2,5^2/6^2,7^2/8^2

4)0,3/4,8/9,24/25,35/36
        can anyone help me ?              

Suppose 

$P(x,y)=\sum_{i+j=0}^N \alpha_{i}x^{i}y^{j}$

is a multivariable polynomial of Nth degree. How may I express the first and second derivatives of $P(x,y)$ through Maplesoft?

Hello Everyone;

Hope you are fine. Solve comand is solving Equation saperately but samultanously. Kindly guide me about this. I have uploaded and pasted the code as well. The last comand (in red color) is not working. I am waiting for the kind response.

Thanks

QuestionNo1.mw

with(GroupTheory);
G := GaloisGroup(x^5 + 20*x + 32, x);

I just can get a result like:

GroupTheory:-GaloisGroup(x^5 + 20*x + 32, x)

But how do I know exactly what group it is? Actually I know the galois group is D₅, But can we use maple to get this information?

Hi! I'm having doubts about the "automatic spacing" in maple. I would like to know two things:

1-can incorrect spacing ruin my code? (Ex by typing "spacebar" too many times )

2- i know that to type spacebar is obligatory after: proc()" "...end proc;    Is there any other situation in wich to use spacebar isn't optional? Thanks for your answers

In the positive range Maple confirms that this is true.
In the real range Maple fails to provide an answer (see attachments).

Is this identity correct?

Download arctan_xy_simplify.mw

and another maybe related case where simplification does not work

arctan_xy_simplify_2.mw

Hello everyone,

I am trying to solve an equation using the "solve(...)" function but the coefficients of the equation are changing.

I am using the coefficients as list but the "solve(...)" function gives error: "Error, (in assuming) when calling 'Engine:-Dispatch'. Received: 'badly formed input to solve: not fully algebraic'"

I am attaching the Maple document.

However, what I want to achieve, is the solution for each value in the list.

Here is an easy example of what I am saying:

a=3*x+k where k=[list of values], a=[another list of values].

I want to find "x" for each pair of values (a,k) in the list.

Thank you !
 

Download LCC_gain_freqFinder.mwLCC_gain_freqFinder.mw

ds := DerivedSeries(PermutationGroup({[[2, 3, 5, 4]], [[1, 2, 3, 4, 5]]}))

will get a series group like:

How to get the group by the red line point out? Then I can use GroupOrder to get the order of it. I note GroupOrder[ds[2]] don't work

Hello, i want to do convert numbers to binary code 8 bytes and I want to sum the digits of each number 

For example first number is 0 i want to write 0 0 0 0 0 0 0 0 , sum=0, for 1= 0 0 0 0 0 0 0 1,  sum =1 for 7= 0 0 0 0 0 1 1 1 sum=3 etc.....
my code is this;

for i from 0 to 10 do;
> S(i):=convert(i,binary);
> end do;

and output is 

> 

                              S(0) := 0
                              S(1) := 1
                              S(2) := 10
                            S(3) := 11
                            S(4):=100
                             S(5) := 101
                             S(6) := 110
                            S(7) := 111
                           S(8) := 1000
                             S(9) := 1001
                            S(10) := 1010
                and  Histogram(S(i));  doesnt work.