MaplePrimes Questions

 I am trying to solve 2 equations in maple:

 1/  solve({1<x or x<3 or x>5});

 {x=x}    solution is correct

 2/  solve({1<x or x<3 or x<5});

 {x<5}    solution is wrong

 How do I have solution correct is {x=x} in Maple?

 Please teach me about this.

 Thank you very much!

Hi there,

Relatively new to maple (and programming all together). I am looking to try and make an if statement that performs several checks but I do not know which order to put them in.

 

Essentially I am trying to start out with i=1, max(Q)>0 and then perform a function, then add 1 to i and run it back through the test again. When my function changes from max(Q)>0 to max(Q)<=0 then I will have found a solution but only if i<330.

I am also unsure if I should put the test for i>330 before or after max(Q) test.


Thank you for any help

 

 

I think that I am probably making this more complicated than it needs to be, but I'm fairly certain that the way that I am doing this is possible within Maple. 

 

Currently I have this line of code

>implicitplot3d({2*sqrt(2)*x-2*z+sqrt(2) = 0, 2*sqrt(2)*x+2*z-sqrt(2) = 0, 2*sqrt(2)*y-2*z-sqrt(2) = 0, 2*sqrt(2)*y+2*z+sqrt(2) = 0}, x = -2 .. 2, y = -2 .. 2, z = -2 .. 2)

 

So these equations create planes that intersect creating a tetrahedron. The problem I'm running into is that I need to "trim" the extra bits of the planes outside of the tetrahedron. The idea I have right now is constraining each plane by 3 equations which would turn the planes into triangles. I think this will work but I'm not sure how to constrain each individual plane with different equations AND plot them on the same graph. Any direction here would be greatly appreciated. I would prefer to stick with using implicitplot3d and avoid any special plotting tools. 

 

Thanks for any help!

The real function y(x) is defined implicitly by the equation:

ln(1+x)*y) + e^((x^2)*(y^2)) = x + cos(x);

How can I find y(0) = 1 and the values of the first six derivatives y(k)(0), k=1, 2,..6 at x=0 to show the Taylorseries about x=0?

(I started by defining p:= ln(1+x)*y) + e^((x^2)*(y^2)) - x - cos(x), but that went wrong. 

 I want to solve PDE by method of lines , i get system of ODEs , I want  to solve this system by rk4 in package can someone help me please 

MOL.mw

I have experimental data that in some respect can be modelled by an asymmetric triangle function.  In the link below is my worsheet examining the effect of making the asymmetric triangle symmetric.  The frequency content, 2*pi*k/T, for both triangles is still the same.  Of course the Fourier coefficients will be different, but it appears the convergence is superior for the symmetric triangle.

I could do this with my experimental data by mirroring it about t=0.  Is this a mistake?  If I can do the symmetric case I think I can fit the data with much fewer terms.  If anyone has experience on these matters I would appreciated your comments.

discontinuty_Fourier_representation.mw

Hi.... I'd want to numerically solve a system of  n  polynomial equations of degree 2 with respect to n unknowns. It seems to me that there is a software in Maple (which deals only with the equations of degree 2) that solves this problem. I cannot find it anymore. Do you know it ? Thanks in advance.

Below is my attempt to evaluate an integral using the substition x=t/T.  MAPLE seems to be upset with my integration limits.  I do not know what I am doing wrong.

(int((1+t/T)*exp(-I*(2*Pi*n*t/T)), t = -T .. 0)+int((1-t/T)*exp(-I*(2*Pi*n*t/T)), t = 0 .. T))/T"(=)"-(1/2)*(cos(2*Pi*n)-1)/(n^2*Pi^2)

x := t/Tau;

1/Tau

(1)

1/2*(int((1+x)*exp(-(I*2)*Pi*n*x), x = -1 .. 0)+int((1-x)*exp(-(I*2)*Pi*n*x), x = 0 .. 1))

Error, (in int) integration range or variable must be specified in the second argument, got t/Tau = -1 .. 0

 

``


 

Download integration_error.mw


Hi

I have to create a function "I(epsilonc)" by integrating a function "sigma(y)"  from 0 to the variable "epsilonc"

but maple doesn t give me the actual formula of the integrated function, it only gives me equation 4 which is utterly useless to me.

 

How do I get Maple to actually calculate and give me the integrated function ??

Any help will be greatly appreciated

restart


#data

`&varepsilon;c1` := 2.1*10^(-3);

0.2100000000e-2

(1)

`&varepsilon;cu1` := 3.5*10^(-3):

Ecm := 31000:

fcm := 25:

Fy := 500:

Es := 200000:

#geometry

As := 1885:

b = 250:

d := 450:


#coefficients

eta := epsilon/`&varepsilon;c1`:

k := 1.05*Ecm*`&varepsilon;c1`/fcm:

``


#formula

 

``

`&sigma;c` := proc (epsilon) options operator, arrow; fcm*(k*epsilon/`&varepsilon;c1`-epsilon^2/`&varepsilon;c1`^2)/(1+(k-2)*epsilon/`&varepsilon;c1`) end proc;

proc (epsilon) options operator, arrow; fcm*(k*epsilon/`&varepsilon;c1`-epsilon^2/`&varepsilon;c1`^2)/(1+(k-2)*epsilon/`&varepsilon;c1`) end proc

(2)

plot(`&sigma;c`, 0 .. `&varepsilon;cu1`);

 

``

#Pressure as a function of y (y=`&varepsilon;c`*y/x) :

`&sigma;c` := proc (y) options operator, arrow; fcm*(k*`&varepsilon;c`*y/(x*`&varepsilon;c1`)-`&varepsilon;c`^2*y^2/(x^2*`&varepsilon;c1`^2))/(1+(k-2)*`&varepsilon;c`*y/(x*`&varepsilon;c1`)) end proc;

proc (y) options operator, arrow; fcm*(k*`&varepsilon;c`*y/(x*`&varepsilon;c1`)-`&varepsilon;c`^2*y^2/(x^2*`&varepsilon;c1`^2))/(1+(k-2)*`&varepsilon;c`*y/(x*`&varepsilon;c1`)) end proc

(3)

Iy := proc (y) options operator, arrow; int(fcm*(k*`&varepsilon;c`*y/(x*`&varepsilon;c1`)-`&varepsilon;c`^2*y^2/(x^2*`&varepsilon;c1`^2))/(1+(k-2)*`&varepsilon;c`*y/(x*`&varepsilon;c1`)), y = 0 .. `&varepsilon;c`/(`&varepsilon;c`+Fy/Es)) end proc;

proc (y) options operator, arrow; int(fcm*(k*`&varepsilon;c`*y/(x*`&varepsilon;c1`)-`&varepsilon;c`^2*y^2/(x^2*`&varepsilon;c1`^2))/(1+(k-2)*`&varepsilon;c`*y/(x*`&varepsilon;c1`)), y = 0 .. `&varepsilon;c`/(`&varepsilon;c`+Fy/Es)) end proc

(4)

Iy(`&varepsilon;c`/(`&varepsilon;c`+Fy/Es))

Error, (in int) integration range or variable must be specified in the second argument, got `&varepsilon;c`/(`&varepsilon;c`+1/400) = 0 .. `&varepsilon;c`/(`&varepsilon;c`+1/400)

 

solve(Iyy*b = Fy*As, `&varepsilon;c`);

``

``


 

Download HW1_-_EC2_strain-pressure_graph.mw
 

restart


#data

`&varepsilon;c1` := 2.1*10^(-3);

0.2100000000e-2

(1)

`&varepsilon;cu1` := 3.5*10^(-3):

Ecm := 31000:

fcm := 25:

Fy := 500:

Es := 200000:

#geometry

As := 1885:

b = 250:

d := 450:


#coefficients

eta := epsilon/`&varepsilon;c1`:

k := 1.05*Ecm*`&varepsilon;c1`/fcm:

``


#formula

 

``

`&sigma;c` := proc (epsilon) options operator, arrow; fcm*(k*epsilon/`&varepsilon;c1`-epsilon^2/`&varepsilon;c1`^2)/(1+(k-2)*epsilon/`&varepsilon;c1`) end proc;

proc (epsilon) options operator, arrow; fcm*(k*epsilon/`&varepsilon;c1`-epsilon^2/`&varepsilon;c1`^2)/(1+(k-2)*epsilon/`&varepsilon;c1`) end proc

(2)

plot(`&sigma;c`, 0 .. `&varepsilon;cu1`);

 

``

#Pressure as a function of y (y=`&varepsilon;c`*y/x) :

`&sigma;c` := proc (y) options operator, arrow; fcm*(k*`&varepsilon;c`*y/(x*`&varepsilon;c1`)-`&varepsilon;c`^2*y^2/(x^2*`&varepsilon;c1`^2))/(1+(k-2)*`&varepsilon;c`*y/(x*`&varepsilon;c1`)) end proc;

proc (y) options operator, arrow; fcm*(k*`&varepsilon;c`*y/(x*`&varepsilon;c1`)-`&varepsilon;c`^2*y^2/(x^2*`&varepsilon;c1`^2))/(1+(k-2)*`&varepsilon;c`*y/(x*`&varepsilon;c1`)) end proc

(3)

Iy := proc (y) options operator, arrow; int(fcm*(k*`&varepsilon;c`*y/(x*`&varepsilon;c1`)-`&varepsilon;c`^2*y^2/(x^2*`&varepsilon;c1`^2))/(1+(k-2)*`&varepsilon;c`*y/(x*`&varepsilon;c1`)), y = 0 .. `&varepsilon;c`/(`&varepsilon;c`+Fy/Es)) end proc;

proc (y) options operator, arrow; int(fcm*(k*`&varepsilon;c`*y/(x*`&varepsilon;c1`)-`&varepsilon;c`^2*y^2/(x^2*`&varepsilon;c1`^2))/(1+(k-2)*`&varepsilon;c`*y/(x*`&varepsilon;c1`)), y = 0 .. `&varepsilon;c`/(`&varepsilon;c`+Fy/Es)) end proc

(4)

Iy(`&varepsilon;c`/(`&varepsilon;c`+Fy/Es))

Error, (in int) integration range or variable must be specified in the second argument, got `&varepsilon;c`/(`&varepsilon;c`+1/400) = 0 .. `&varepsilon;c`/(`&varepsilon;c`+1/400)

 

solve(Iyy*b = Fy*As, `&varepsilon;c`);

``

``


 

Download HW1_-_EC2_strain-pressure_graph.mw

 

Possibly related to this. One has to remember that the result of convert/MeijerG for sin(z) is actually csgn(z)*sin(z):

convert(sin(z), MeijerG, include = all);
         sqrt(Pi)*MeijerG([[], []], [[1/2], [0]], (1/4)*z^2)

simplify(%);
         csgn(z)*sin(z)

That is the case for some other functions as well. Wouldn't it be better to return csgn(z)*MeijerG? For the sine, the form z*MeijerG is also a possibility. Might help to avoid issues similar to this one:

int(sin(a*x)*MeijerG([[], []], [[0], []], x)/x, x = 0 .. infinity); # incorrect for Re(a)<0
             -arctan(1/a)+(1/2)*Pi

 

I know that the Fourier transform of the triangle function is the sinc function squared, but I cannot seem to reproduce this in MAPLE.  How do I get from R2 to the square of the sinc function or do I have a screw up in defining the integral?  I need another set of eyes.  I have been at this for awhile & cannot seem to breakthrough.


 

plot(piecewise(-1 < x and x < 0, 1+x, 0 < x and x < 1, 1-x), x = -2 .. 2, linestyle = solid, thickness = 5, scaling = constrained, title = "Symmetric Triangle Wave")

 

(int((1+t)*exp(-I*(2*Pi*n*t/T)), t = -(1/2)*T .. 0)+int((1-t)*exp(-I*(2*Pi*n*t/T)), t = 0 .. (1/2)*T))/T = ((-(2*I)*n*Pi-T+I*T*n*Pi)*exp(I*n*Pi)+(2*I)*n*Pi+T-(2*I)*n*Pi+T+((2*I)*n*Pi-T-I*T*n*Pi)*exp(-I*n*Pi))/(2^2*n^2*Pi^2)
"(->)"true"(->)"true

(int((1+t)*exp(-I*(2*Pi*n*t/T)), t = -(1/2)*T .. 0)+int((1-t)*exp(-I*(2*Pi*n*t/T)), t = 0 .. (1/2)*T))/T = ((-T+I*T*n*Pi)*exp(I*n*Pi)+2*T-(T+I*T*n*Pi)*exp(-I*n*Pi))/(2^2*n^2*Pi^2)
"(->)"true"(->)"true

R1 := ((-T+I*T*n*Pi)*exp(I*n*Pi)+2*T-(T+I*T*n*Pi)*exp(-I*n*Pi))/(2^2*n^2*Pi^2)

(1/4)*((-T+I*T*n*Pi)*exp(I*n*Pi)+2*T-(T+I*T*n*Pi)*exp(-I*n*Pi))/(n^2*Pi^2)

(1)

R1 = (1/4)*(2*T-T*(exp(-I*n*Pi)+exp(I*n*Pi))-I*(exp(-I*n*Pi)-exp(I*n*Pi))*Pi*T*n)/(n^2*Pi^2)"(->)"true

NULL

exp(-I*n*Pi)+exp(I*n*Pi)"(=)"2*cos(Pi*n)

exp(-I*n*Pi)+exp(I*n*Pi) = 2*cos(Pi*n)"(->)"false

exp(-I*n*Pi)-exp(I*n*Pi)"(=)"-(2*I)*sin(Pi*n)

exp(-I*n*Pi)-exp(I*n*Pi) = -(2*I)*sin(Pi*n)"(->)"false

R2 := (1/4)*(-2*cos(Pi*n)*T-2*sin(Pi*n)*T*n*Pi+2*T)/(n^2*Pi^2)

(1/4)*(-2*cos(Pi*n)*T-2*sin(Pi*n)*T*n*Pi+2*T)/(n^2*Pi^2)

(2)

R2 = 2*T*(1-cos(Pi*n)-Pi*n*sin(Pi*n))/(2^2*n^2*Pi^2)"(->)"true"(->)"true"(->)"true"(->)"true"(->)"true

-2*cos(Pi*n)*T-2*sin(Pi*n)*T*n*Pi+2*T"(=)"-2*T*(cos(Pi*n)+Pi*n*sin(Pi*n)-1)``

1-cos(a) = 2*sin((1/2)*a)^2"(->)"true

(1/2)*(-exp(I*n*Pi)+1+I*n*Pi)/(Pi^2*n^2)-(1/2)*(I*exp(I*n*Pi)*Pi*n-exp(I*n*Pi)+1)*exp(-I*n*Pi)/(Pi^2*n^2) = (1/2)*(2-exp(I*n*Pi)-exp(-I*n*Pi))/(Pi^2*n^2)"(->)"true

2-exp(I*n*Pi)-exp(-I*n*Pi) = -exp(-I*n*Pi)*(exp(I*n*Pi)-1)^2"(->)"true

2-exp(I*n*Pi)-exp(-I*n*Pi) = -exp(-I*n*Pi)*(exp(I*n*Pi)-exp(I*n*Pi)*exp(-I*n*Pi))^2"(->)"true

2-exp(I*n*Pi)-exp(-I*n*Pi) = -exp(-I*n*Pi)*(exp(I*n*Pi)*(exp(I*n*Pi)-exp(-I*n*Pi)))^2"(->)"true"(->)"true

2-exp(I*Pi*n)-exp(-I*Pi*n) = -exp(-I*Pi*n)*exp((2*I)*Pi*n)*(exp(I*Pi*n)-exp(-I*Pi*n))^2"(->)"true"(->)"true

exp(I*Pi*n)-exp(-I*Pi*n)"(=)"(2*I)*sin(Pi*n)

``


 

Download symmetric_triangle_fourier_coeffs.mw

Why does MAPLE do this?  Check the link
 

exp(I*n*Pi)+exp(-I*n*Pi)"(=)"2*cos(Pi*n)

exp(-I*n*Pi)+exp(I*n*Pi) = 2*cos(n*Pi)"(->)"false

exp(-I*n*Pi)-exp(I*n*Pi)"(=)"-(2*I)*sin(Pi*n)

exp(-I*n*Pi)-exp(I*n*Pi) = -(2*I)*sin(n*Pi)"(->)"false``

``


 

Download Eulers_formula.mw

 

This question caught my eye on Mathematics Stack Exchange forum and doesnt seem to be resolved even with Mapel 2017.3:

Please follow the question and the discussion here

The question simply is to find the Fourier Transform of arctan(x)/x and use its inverse to verify if the solution provided by Maple was consistent.

The same sequence was tested on Wolfram Mathematica, and correct result was obtained.

Experienced users on this forum please advise what could be the possible explaination for this result.

Maple test:

Hi all, 

I am stuck in the follow sum:

Write a procedure to evaluate the sum of Sn and use this to find the value of n=10^p, p=1,2,3,4,5.

I started with defining Sn, 

restart:
Sn:=sum((1/k^(1/10))*sin(1/k), k=1..n);

Perhaps sum is not the correct one? Perhaps add?

And help appreciated

 

First 822 823 824 825 826 827 828 Last Page 824 of 2354