# Items tagged with studentstudent Tagged Items Feed

### Solution of a system?...

July 27 2015
1 5

Cheers!

I'm having a problem with my student work, about to have a solution of 6 equations... Can help me in this file? i dont know how to solve this... this had-me a null solve...

Thanks for the help =)

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### Positivity of a huge polynomial...

July 24 2015
1 5

I need to show that the following expression,
a^3b-a^3c+a^3z+a^3x+a^3y-a^2bx+a^2by+a^2cx-a^2cy-a^2zx+a^2zy-a^2x^2+a^2y^2-abcz-abcx-aczx-acx^2+b^2c^2+2bc^2x+c^2x^2-b^2c-2bcx-cx^2,

is positive

given that:

1. a,b,c,x,y,z are positive real numbers

2. a>b+x

3. c<b+y

I know a priori that the expression is indeed positive, but I do not know how to show it, or how to use Maple to do it?

Specifically, how can I use Maple to **partially factorize** the expression in terms of the expressions a-b-x and c-b-y?

Thanks for any help.

### Have I bought Maple uselessly? ...

July 22 2015
2 3

I have purchased Maple 2015 Student Edition a few months ago.  Now, I was about to buy MapleSim Student Edition and I saw that MapleSim include a license of Maple.

If I buy MapleSim and Maple,  I would pay 198$even if I could have bought only MapleSim and still get both products? Can I get MapleSim Student without Maple at a lower price? Maybe the version of Maple included in MapleSim has less features and that's why the cost of MapleSim and Maple are the same? Thanks in advance! I did some search on Google and on this website, but I haven't found anything. ### beginner/beam basic design... July 22 2015 0 1 please demonstrate to me how to set up a maple document to solve a simple beam design from the scratch. S. Hassan ### Student input as variable in Maple TA assignment... July 14 2015 1 1 Is it possible to have an input box, where the student can give an input (integer) and this is then used in the following questions in an assignment? e.g. in the first question the student is asked to give his student number, in the second question this number is used to create random parameters. ### IVP Dsolve Error... July 11 2015 1 1 Hello, I am a student doing some self study over the summer trying to work through some of the John Taylor computer problems from his classcial mechanics book. Currently I hit a snag that most likely comes from the fact I am not well acquinted with Maple for solving IVP and DE's (we used Matlab in my DE class). I just need to know how I remove the following error: Error, (in dsolve/numeric/SC/IVPsetup) initial conditions must be numeric Here is a copy of my code: R := 5; 5 g := 9.8; 9.8 deq1 := {diff(x(t), [$(t, 2)]) = -g*sin(x(t))/R, x(0) = 20};
/ d / d \ \
{ --- |--- x(t)| = -1.960000000 sin(x(t)), x(0) = 20 }
\ dt \ dt / /
dsol1 := dsolve(deq1, numeric);
Error, (in dsolve/numeric/SC/IVPsetup) initial conditions must be numeric

My hunch is that I need to set x'(0)=0 or something like I do not have enough intial values to solve the problem, but I could be wrong. Anyway anyone who can point out my mistake feel free to do so! Thank you!

### CURVATURE OF GENERALIZED SASAKIAN SPACE FORMS...

July 02 2015
1 1

Given an almost contact metric manifold M(\phi,\xi,\eta, g), we say
that M is a generalized Sasakian-space-form if there exist three functions f1, f2, f3
on M such that the curvature tensor R is given by

R(X,Y)Z=f_1{g(Y,Z)X-g(X,Z)Y}+f_2{g(X,\phiZ)\phiY-g(Y,\phiZ)\phiX+2g(X,\phiY)\phiZ}+f_3{\eta(X)\eta(Z)Y-\eta(Y)\eta(Z)X+gg(X,Z)\eta(Y)\xi-g(Y,Z)\eta(X)\xi}

In (2n+1) dimensional generalized Sasakian space form M2n+1(f_1,f_2,f_3), we have the following relations.

S(X,Y)=(2nf_1+3f_2-f_3)g(X,Y)-(3f_2+(2n-1)f_3)\eta(X)\eta(Y)

S(X,\xi)=2n(f_1-f_3)\eta(X)

C\bar(\xi,X)Y=[f_1-f_3-(r/2n(2n-1))][g(X,Y)\xi-\eta(Y)X]

P(X,Y)Z=R(X,Y)Z-(1/(n-1))[S(Y,Z)X-S(X,Z)Y]

R(X,Y)\xi=(f_1-f_3){\eta(Y)X-\eta(X)Y}

R(\xi,X)Y=(f_1-f_3){g(X,Y)\xi-\eta(Y)X}

for any vector fields X, Y on M, where R, S, C\bar, and r denote the Riemannian curvature tensor, Ricci tensor, concircular curvature tensor and scalar curvature of M2n+1(f1, f2, f3), respectively

Using above equations I have to evaluate P(C\bar(\xi,X)Y,Z)U.

Manually It is tedious job. Can we find the value by maple? Is there any option to solve these type of problems?

If yes, I can solve many more, which helps a lot in my work.. Thanks in advance.

### Rational functions and CylindricalAlgebraicDecompo...

June 25 2015
0 2

Maybe a bit strange question (just exploring Maple and a new topic), but is there a way to use CylindricalAlgebraicDecompose with a rational functions, eg 1/x, where eg is x an integer? I tried to use it but always ended up with:

Error, invalid input: RegularChains:-SemiAlgebraicSetTools:-CylindricalAlgebraicDecompose expects its 1st argument, F, to be of type Or(list(list(Or(polynom(rational), polynom(rational) = polynom(rational), polynom(rational) <> polynom(rational), polynom(rational) <= polynom(rational), polynom(rational) < polynom(rational)))), list(polynom(rational))), but received [1/x = x, polynom(rational)]

### How to read some outputs from RegularChain package...

June 25 2015
1 4

Hi! I just started to use Maple and I play with some of its functions. I have seen in examples related to RegularChain package an output like  [regular_chain, [[-1, -1], [0, 0]]] and I wonder how I should read it. Thanks for any help and sorry if my question is very basic.

### How to input calculated coefficients to correspond...

June 12 2015
1 1

I have calculated coefficients in maple using a "for...end do" command. For example,

for n from 0 to 1 do A[n] = int(((2*n+1)*(1/2))*simplify(LegendreP(n, cos(theta)))*sin(theta), theta = 0 .. (1/2)*Pi) end do;

A[0] = 1/2

A[1] = 3/4

Here, I can calculate as many coefficients as I want. But, how do I use these coefficients in the following line? For example, I need to calculate a summation. But for each term in the summation, I want to input the coefficients above to the corresponding term in the sum. So. the following summation

A[0]+A[1]*r*cos(theta)+...

will automaticlly attach the numerical values of the coefficients calculated above to the corresponding term in the sum.

I hope this makes sense.

### How to determine unknown value in boundary conditi...

June 11 2015
0 6

Hello everyone,

How can unknown values in boundary conditions of system ODEs be determine by using shooting technique. See the work sheet here Sht.mw

Thanks.

### Is there some kind of commands?...

June 05 2015
0 2

This command (Student[Calculus1][ShowSolution](Int(e^(-(s-1)*t)))) shows me solutions.

and, the command in the picture can make integral solution but not laplace

so i ask you that what command make solutions for Laplace transform

### Error, (in plot) two lists or Vectors of numerical...

June 03 2015
1 2

Hey there,

I've a numerical solved system of differential equations, which depend on one argument and one index. I can solve it, but when I try plot it I have this error: Error, (in plot) two lists or Vectors of numerical values expected.

Could anyone help me figure out what I'm doing wrong?

> restart;
> A := 115.1558549; B := .3050464658; n := 3; f0 := 0.5e-4;

>f:=theta->f0*(cos(arcsin(sin(theta)/n)))^2;
I0:=Ir(z)+sum(Is[k](z),k=1..20);

> alpha := [0, 1, 2, 3, 4, 5, 6];

Theta := [3*Pi*(1/180), 6*Pi*(1/180), 9*Pi*(1/180), 12*Pi*(1/180), 15*Pi*(1/180), 18*Pi*(1/180), 21*Pi*(1/180), 24*Pi*(1/180), 27*Pi*(1/180), 30*Pi*(1/180), 33*Pi*(1/180), 36*Pi*(1/180), 39*Pi*(1/180), 42*Pi*(1/180), 45*Pi*(1/180), 48*Pi*(1/180), 51*Pi*(1/180), 54*Pi*(1/180), 57*Pi*(1/180), 60*Pi*(1/180)];

>G:= theta->A*sin(theta)*cos(2*arcsin((sin(theta)/n)))/((1+sin(theta)^2/B^2)*cos(arcsin(sin(theta)/n)));

>for j from 1 to 7 do
d1 := diff(Ir(z), z) = -sum(G(Theta[k])*Ir(z)*Is[k](z)/I0,k=1..20)-alpha[j]*Ir(z)-sum(f(Theta[k])*Ir(z),k=1..20):
d2 := diff(Is[1](z), z) = G(Theta[1])*Ir(z)*Is[1](z)/I0-alpha[j]*Is[1](z)+f(Theta[1])*Ir(z):
d3 := diff(Is[2](z), z) = G(Theta[2])*Ir(z)*Is[2](z)/I0-alpha[j]*Is[2](z)+f(Theta[2])*Ir(z):
d4 := diff(Is[3](z), z) = G(Theta[3])*Ir(z)*Is[3](z)/I0-alpha[j]*Is[3](z)+f(Theta[3])*Ir(z):
d5 := diff(Is[4](z), z) = G(Theta[4])*Ir(z)*Is[4](z)/I0-alpha[j]*Is[4](z)+f(Theta[4])*Ir(z):
d6 := diff(Is[5](z), z) = G(Theta[5])*Ir(z)*Is[5](z)/I0-alpha[j]*Is[5](z)+f(Theta[5])*Ir(z):
d7 := diff(Is[6](z), z) = G(Theta[6])*Ir(z)*Is[6](z)/I0-alpha[j]*Is[6](z)+f(Theta[6])*Ir(z):
d8 := diff(Is[7](z), z) = G(Theta[7])*Ir(z)*Is[7](z)/I0-alpha[j]*Is[7](z)+f(Theta[7])*Ir(z):
d9 := diff(Is[8](z), z) = G(Theta[8])*Ir(z)*Is[8](z)/I0-alpha[j]*Is[8](z)+f(Theta[8])*Ir(z):
d10 := diff(Is[9](z), z) = G(Theta[9])*Ir(z)*Is[9](z)/I0-alpha[j]*Is[9](z)+f(Theta[9])*Ir(z):
d11 := diff(Is[10](z), z) = G(Theta[10])*Ir(z)*Is[10](z)/I0-alpha[j]*Is[10](z)+f(Theta[10])*Ir(z):
d12 := diff(Is[11](z), z) = G(Theta[11])*Ir(z)*Is[11](z)/I0-alpha[j]*Is[11](z)+f(Theta[11])*Ir(z):
d13 := diff(Is[12](z), z) = G(Theta[12])*Ir(z)*Is[12](z)/I0-alpha[j]*Is[12](z)+f(Theta[12])*Ir(z):
d14 := diff(Is[13](z), z) = G(Theta[13])*Ir(z)*Is[13](z)/I0-alpha[j]*Is[13](z)+f(Theta[13])*Ir(z):
d15 := diff(Is[14](z), z) = G(Theta[14])*Ir(z)*Is[14](z)/I0-alpha[j]*Is[14](z)+f(Theta[14])*Ir(z):
d16 := diff(Is[15](z), z) = G(Theta[15])*Ir(z)*Is[15](z)/I0-alpha[j]*Is[15](z)+f(Theta[15])*Ir(z):
d17 := diff(Is[16](z), z) = G(Theta[16])*Ir(z)*Is[16](z)/I0-alpha[j]*Is[16](z)+f(Theta[16])*Ir(z):
d18 := diff(Is[17](z), z) = G(Theta[17])*Ir(z)*Is[17](z)/I0-alpha[j]*Is[17](z)+f(Theta[17])*Ir(z):
d19 := diff(Is[18](z), z) = G(Theta[18])*Ir(z)*Is[18](z)/I0-alpha[j]*Is[18](z)+f(Theta[18])*Ir(z):
d20 := diff(Is[19](z), z) = G(Theta[19])*Ir(z)*Is[19](z)/I0-alpha[j]*Is[19](z)+f(Theta[19])*Ir(z):
d21 := diff(Is[20](z), z) = G(Theta[20])*Ir(z)*Is[20](z)/I0-alpha[j]*Is[20](z)+f(Theta[20])*Ir(z):
dsys := {d1, d10, d11, d12, d13, d14, d15, d16, d17, d18, d19, d2, d20, d21, d3, d4, d5, d6, d7, d8, d9}:
dSol[j] := dsolve({op(dsys), Ir(0) = 1, Is[1](0) = 0.1e-1, Is[2](0) = 0.1e-1, Is[3](0) = 0.1e-1, Is[4](0) = 0.1e-1, Is[5](0) = 0.1e-1, Is[6](0) = 0.1e-1, Is[7](0) = 0.1e-1, Is[8](0) = 0.1e-1, Is[9](0) = 0.1e-1, Is[10](0) = 0.1e-1, Is[11](0) = 0.1e-1, Is[12](0) = 0.1e-1, Is[13](0) = 0.1e-1, Is[14](0) = 0.1e-1, Is[15](0) = 0.1e-1, Is[16](0) = 0.1e-1, Is[17](0) = 0.1e-1, Is[18](0) = 0.1e-1, Is[19](0) = 0.1e-1, Is[20](0) = 0.1e-1}, [Ir(z), Is[1](z), Is[2](z), Is[3](z), Is[4](z), Is[5](z), Is[6](z), Is[7](z), Is[8](z), Is[9](z), Is[10](z), Is[11](z), Is[12](z), Is[13](z), Is[14](z), Is[15](z), Is[16](z), Is[17](z), Is[18](z), Is[19](z), Is[20](z)], numeric);
end do:

>for j from 1 to 7 do
dSol[j](0.4);
as:='as':
for l from 1 to 20 do
as[l]:=[Theta[l],rhs(dSol[j](0.4)[2+l])];
od:
plo[j]:=convert(as,listlist);
od:

>plot(plo[2],plo[1]);
Error, (in plot) two lists or Vectors of numerical values expected

### What does unable store mean?...

June 01 2015
1 9

Hello everyone,

I'm trying to solve system of ODE but it return this Error, (in fproc) unable to store 'YP[4]' when datatype=float[8]
How can this be corrected, see the worksheet YP.mw

Thanks.

### Changing significant digits gives different answer...

June 01 2015
0 5

Hi,

Why does maple do this? For example:

>Digits := 4

>.67*((6918*(.856*11+1.08))/(42.2*2600^.36))^5;

=7.216 10^9

But with the Digit set to default it gives me:

>.67*((6918*(.856*11+1.08))/(42.2*2600^.36))^5;

=7.204144575 10^9

thanks!

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