## Substitution Tensor command has problem with numbe...

I am having trouble with the SubstitutionTensor command.  It kicks out an error message for operand with different free indices, but the operands seems to be fine.  I checked all of the terms and they all seem fine. Thank you for your help.

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## DirectSearch result...

hi

DirectSearch answer has confused me. How to reduce the residual.
See the program.Direct.mw

## Which versions of Maple 18 (Personal, Academic, Co...

I'm interested in doing some experimental mathematics using the PSLQ integer relation algorithm.  The only third-party program for doing PSLQ problems I've been able to find is a GNU C++ program with a less-than-user-friendly command-line interface.  I've heard that Maple implements PSLQ and I like the symbolic input and presentation it offers as a CAS, but I can't find any information on which alternative types of Maple 18 make the PSLQ algorithm available.

## solving periodic trigonomic equations...

Hi Maple friends. :)

I would like to graph and solve: 2*sin(2 x)=1 for the interval 0<=x<=360. My textbook gives the answers of x=15, 75, 195 and 225.

But I get an error messages:

plot(2*sin(2*x) = 1, x = 0 .. 360);
Error, invalid input: plot expects its 1st argument, p, to be of type {array, list, rtable, set, algebraic, procedure, And(`module`, appliable)}, but received 2*sin(2*x) = 1

solve(2*sin(2*x) = 1, x = 0 .. 360);
Error, invalid input: too many and/or wrong type of arguments passed to solve; first unused argument is x = 0 .. 360

Any help would be appreciated! Thanks in advance.

## Maple as a teaching tool...

Hi all. I am using Maple 18.

1. Does Maple only output an answer, or can it be made to display the steps it took to achieve the result, in a way that is logical and understandable by the user? For example, I would like to see it display steps when integrating or differentiating, or dividing a polynomial by another polynomial. Basically any process that involve simplifyinf or factorisation.

2. I am trying to divide x^2 + 5x + 9 by x+2, but all Maple displays is the expression

How can I make it do the polynomial division and output the steps it took? I tried using simplify and evaluate from the context menu but the output is still just the expression.

3. Has something happened to this site? It was working fine in Opera until two days ago, and has sinmce started displaying "Error generating page" where the replies to questions should be. No problems with the "posts" section, only in the "questions" section.

## a couple of newbie questions...

Hi all. I am using Maple 18.

1. How can I make maple NOT plot discontinuties with a vertical line? For example, plotting y=tan(x) displays vertical lines. Is there a setting to turn this off permanently?

2. When I type y=sin(x-Pi/2) and press enter, y = -cos(x) is displayed in blue. I am sure they are both the same thing, but I would like to see the expression that I typed, not an alternate expression that Maple wants to display.

3. Why do some expressions require a ; at the end, whilst others don't? Ie. y = sin(x) and y = 1+sin(x) do not, but y=2*sin(x) results in a "Warning, inserted missing semicolon at end of statement"

4. Is there a section on Mapleprimes(this site) where new users can ask questions? I would like to browse it to see what sort of problems other new Maples users have encountered. I am sure that my above questions may have been asked a few times over the years by newbies like myself.

## Introduction to Thermodynamics

Maple 18

With this contribution we opened a breach in the proper use of the program applied Thermodynamics.

Introducción_a_la_Termodinámica.mw     (in spanish)

## Problem on the solution of Trigonometric Equations...

How can I know the solution is correct??

Here is the code:

s := solve(sin(x^2) = 1/2);
test := subs(x = s[1], sin(x^2) = 1/2);

## Avoid print quotes in maple output...

Hi all,

i have the following problem:

i had create this tiny procedure to compute the berstein base elements:

And so i would like print space, between B(i,n,t) and the formula corresponing, without quotes :D

In other word i would an output like this:

B(i,n,t),      ,(formula)

## Implicit Differentiation...

sin(xy) = x + y

subs( y(x)=y, solve( diff(subs( y=y(x), (1) ),x), diff(y(x),x) ) );

-1

subs( x(xy)=x, solve( diff(subs( x=x(xy), (1) ),xy), diff(x(xy),xy) ) );

cos(xy)

1- y cos(xy)

--------------

x cos(xy) - 1

And is there a way that this program can tutor me on how to get this answer intead of spitting out the answer

the diff tutor only allows for a one sided equation to be entered.

## differentiation by "Diff"...

Hi. I want to differentiate the following expression using "Diff", not "diff". but I want to apply "Diff" to differentiate each separate term based on the chain rule. How can I do that? Does "Diff" apply chain rule for differentiation?

Hi Everyone,

I just upgraded a Linux 64-bit computer from Maple 17 to Maple 18.01.  Code that worked on Maple 17 no longer works on Maple 18.01.  The code uses BLAS matrix operations in in the LinearAlgebra package.  When the first such operation is called, I obtain the following fatal error:

Maple 18.01 is unable to load any of the MKL routines even though the MKL shared libraries are in the Linux bin directory.  If I load my own MKL library (provided by Intel), Maple 18 will run these operatrions, but they ultimately lose precision which causes the program (which works fine in 17) to crash.  Any ideas about how to activate the version of MKL provided by Maple?  Will this version not loose floating-point precision?  Any help is greatly appreciated.

Best wishes.

David

University of Chicago

## Solution of quite complicated equation in terms of...

This is my code for finding mode shapes and critical load for a bimaterial strut under buckling.

Although everything else is working fine but I have a problem while solving for critical load.

h_new := convert(series(h, P, 3), polynom):

h_new := convert(series(h, P, 3), polynom):

without converting to polynomial, the code is unable to solve for P. Even on conversion, for differnet S values, I need to change the truncation order of conversion (like for S=0.5, it would work with 3 but for other S values I have to change truncation (convert(series(h, P, 6), polynom)), which also causes the number of solutions of equation to change which causes problem with plotting of graphs of critical load that I need (basically I need lowest two plots), thereby restricts me from automating the code with a for loop. I need to test it for various S values and then later in code I need to put teh critical load back and check mode shapes for different a values.

Is there a better way to solve two variable equation to get one variable in terms of another(the equation is quite complicated, contains trigonometric expressions).

and also if I try to automate the analysis for different S and a values, teh process needs to put teh value back in P which changes everything and teh next time loop operates it just ruins everything. Also there are varied number of solutions of P_crit for differnet S values which makes it difficult to store those solutions during automation?

## data table export...

hi,

I want to solve this to data table , i can plot but i need data in table

sol1 := dsolve([diff(u(theta),theta) = 427.2461*u(theta)+385620.123/u(theta)-25671.3871, u(0) = .6], numeric);

plots[odeplot](sol1, 0..0.18, color = red);

thanks.

## reliability result of DirectSearch...

how i can trust in DirectSearch solution result.is there any creteria?

my variable is intensity.

this is my code:

ep0 := 1/(4*3.14); el := 8.54*10^(-2); hbar := 1; vf := 1/300; kb := 1; tem := 2.586*10^(-2); ci := 1; p := 1.458*10^16; beta := 2; ai := 7.1*10^(-4); bi := ai/sqrt(3); enph := .196; d := enph/(kb*tem); n0 := 1/(exp(enph/(kb*tem))-1); gama := hbar*vf; intensity := 10000001; w := 1.55; impurity := 7.2*10^3;

g := hbar*beta/(bi^2*sqrt(2*p*enph)); aa := g^2*(n0+1)/(2*Pi*hbar*gama^2); bb := g^2*n0/(2*Pi*hbar*gama^2); cc := 2/(Pi*gama^2); l := (1*hbar)*w/(2*kb*tem);u := el^2*intensity/(32*w*hbar^2);

DirectSearch:-SolveEquations([op([((enph*ln(1+exp(c+enph/(kb*tem)))/(kb*tem)-polylog(2, -exp(c))+polylog(2, -exp(c+enph/(kb*tem))))*enph*(kb*tem)^2-(enph^2*ln(1+exp(c+enph/(kb*tem)))/(kb^2*tem^2)+2*enph*polylog(2, -exp(c+enph/(kb*tem)))/(kb*tem)+2*polylog(3, -exp(c))-2*polylog(3, -exp(c+enph/(kb*tem))))*(kb*tem)^3+(-exp(b)*enph*ln(1+exp(c+enph/(kb*tem)))+exp(c+d)*enph*ln(1+exp(b-d+enph/(kb*tem)))+exp(b)*kb*tem*polylog(2, -exp(c))-exp(c+d)*kb*tem*polylog(2, -exp(b-d))-exp(b)*kb*tem*polylog(2, -exp(c+enph/(kb*tem)))+exp(c+d)*kb*tem*polylog(2, -exp(b-d+enph/(kb*tem))))*enph*(kb*tem)^2/((exp(b)-exp(c+d))*kb*tem)+(exp(b)*enph^2*ln(1+exp(c+enph/(kb*tem)))-exp(c+d)*enph^2*ln(1+exp(b-d+enph/(kb*tem)))+2*exp(b)*enph*kb*tem*polylog(2, -exp(c+enph/(kb*tem)))-2*exp(c+d)*enph*kb*tem*polylog(2, -exp(b-d+enph/(kb*tem)))+2*exp(b)*kb^2*tem^2*polylog(3, -exp(c))-2*exp(c+d)*kb^2*tem^2*polylog(3, -exp(b-d))-2*exp(b)*kb^2*tem^2*polylog(3, -exp(c+enph/(kb*tem)))+2*exp(c+d)*kb^2*tem^2*polylog(3, -exp(b-d+enph/(kb*tem))))*(kb*tem)^3/((exp(b)-exp(c+d))*kb^2*tem^2))*bb+u*(1/(1+exp(-l-c))-1/((1+exp(-l-c))*(1+exp(l-b))))-(((1*enph)*(enph-2*kb*tem*ln(1+exp(-b+enph/(kb*tem))))/(2*kb^2*tem^2)+2*kb^2*tem^2*(-polylog(2, -exp(-b+enph/(kb*tem)))+polylog(2, -cosh(b)+sinh(b))))*enph*(kb*tem)^2-(enph^2*(enph-3*kb*tem*ln(1+exp(-b+enph/(kb*tem))))-6*kb^2*tem^2*(enph*polylog(2, -exp(-b+enph/(kb*tem)))+kb*tem*(-polylog(3, -exp(-b+enph/(kb*tem)))+polylog(3, -cosh(b)+sinh(b)))))*(kb*tem)^3/(3*kb^3*tem^3)-(-exp(b)*enph^2+exp(c+d)*enph^2-2*exp(c+d)*enph*kb*tem*ln(1+exp(-b+enph/(kb*tem)))+2*exp(b)*enph*kb*tem*ln(1+exp(-c-d+enph/(kb*tem)))+2*exp(c+d)*kb^2*tem^2*polylog(2, -exp(-b))-2*exp(b)*kb^2*tem^2*polylog(2, -exp(-c-d))-2*exp(c+d)*kb^2*tem^2*polylog(2, -exp(-b+enph/(kb*tem)))+2*exp(b)*kb^2*tem^2*polylog(2, -exp(-c-d+enph/(kb*tem))))*enph*(kb*tem)^2/((2*(-exp(b)+exp(c+d)))*kb^2*tem^2)-(exp(b)*enph^3-exp(c+d)*enph^3+3*exp(c+d)*enph^2*kb*tem*ln(1+exp(-b+enph/(kb*tem)))-3*exp(b)*enph^2*kb*tem*ln(1+exp(-c-d+enph/(kb*tem)))+6*exp(c+d)*enph*kb^2*tem^2*polylog(2, -exp(-b+enph/(kb*tem)))-6*exp(b)*enph*kb^2*tem^2*polylog(2, -exp(-c-d+enph/(kb*tem)))+6*exp(c+d)*kb^3*tem^3*polylog(3, -exp(-b))-6*exp(b)*kb^3*tem^3*polylog(3, -exp(-c-d))-6*exp(c+d)*kb^3*tem^3*polylog(3, -exp(-b+enph/(kb*tem)))+6*exp(b)*kb^3*tem^3*polylog(3, -exp(-c-d+enph/(kb*tem))))*(kb*tem)^3/((3*(-exp(b)+exp(c+d)))*kb^3*tem^3))*aa-u*(1/(1+exp(l-b))-1/((1+exp(-l-c))*(1+exp(l-b)))) = 0, -cc*polylog(2, -exp(b))+cc*polylog(2, -exp(-c))-impurity = 0])], tolerances = 10^(-8), evaluationlimit = 20000)

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