## How to reference and evaluate the equation when it...

I am not sure if this is a general problem.  And I am considering the best way to evaluate the expression (Equation) when it contains variables which have been modified by using assume.   Here is a tiny test example:

restart;
assume(a>0,x>0);
int(int(x^2/y^2,y=1/x..x),x=1..a);S:=%:
1  4   1   1  2

## Too many levels of recursion (Roots)...

t0 := arccosh(lambda/(s*(1-lambda)))

f := int(sqrt(lambda-s*cosh(t)/(1+s*cosh(t))), t = -t0 .. t0)

s := 1/10

with(Student[Calculus1])

g := f-Pi*(0+1/2)

Roots(g, lambda = 0 .. 1, numeric)

Why does maple say:

Error, (in mod/Expand) too many levels of recursion?

## Plotting a solution of an ode...

r(t) = RootOf(Int(_a/sqrt(-4*_a^4+5*_a^2-1), _a = 1 .. _Z)+t), r(t) = RootOf(Int(_a/sqrt(-4*_a^4+5*_a^2-1), _a = _Z .. 1)+t), r(t) = RootOf(Int(_a/sqrt(-4*_a^4+13*_a^2-9), _a = 1 .. _Z)+t), r(t) = RootOf(Int(_a/sqrt(-4*_a^4+13*_a^2-9), _a = _Z .. 1)+t)

ist my result of an ODE

g := dsolve([oder, r(0) = 1, (D(r))(0) = 0])

oder := diff(r(t), t, t) = 4*sqrt(1-(diff(r(t), t))^2)+(1-(diff(r(t), t))^2)/r(t)

Now usually maple gives me one solution, so I can just plot with

## Calculus Integration Tutor bug

by: Maple 17

I'm fairly sure I discovered a bug with the Maple 17 Calculus Integration tutor.

I was working on int((x^2+2*x)*cos(x), x);.

The first step that the tutor wants you to do is to rewrite the integral by factoring out an x from the first term, and changing cos(x) to -sin(x).

The next step is to rewrite it again, this time changing sin to cos, making the intergal  -x(x+2)cos(x)

Next, the tutor distributes the X again, making the integral -(x^2+2*x...

## Very special evaluation rules of `if`...

In the following code, why is B returned unevaluated?

`restart:A:= a:  B:= 2:F:= _a-> eval(`if`(A,B,C), a= _a):F(true);                               Beval(B);                   ...`

## simplify expression...

-(1/2*I)*(I*Pi*ln(2)-I*Pi*ln(g+4)-2*ln(2)^2+2*ln(2)*ln(g+4)-2*ln(2)*ln(-1/2*I)+ln(g+4)*ln(-1/2*I)-ln(g+4)*ln(2*I)+ln(-1/2*I)*ln(4-g)+ln(4-g)*ln(2*I))/Pi

why doesnt maple simplify this expression any further?

but he complains when using combine saying:

Error, (in combine/ln) second argument must be a maple type

Why is that?

## Problems with 17.01...

Yesterday I’ve updated to the new Version 17.01 and now I’ve the problem that I cannot enter  ‚}‘ and another problem is an exponent e. g. x^2. To enter it I have to write x^22. The first number is not shown in the worksheet.

I hope someone can help me to solve this problem.

## calculating with lists...

i have a list of numeric values like this:

r:=[a,b,c,....]

now i want to calculate the quantity

s:=lambda-r^2

which in turn should give me a list again whose entries are:

[lambda-a^2,lambda-b^2,...]

but just doing

s:=lambda-r^2 doesnt work.

lambda is an arbitrary number

## solving inequality with restrictions and parameter...

Hi,

I want to check this inequality (check below) for the set of parameters that holds, and I also want to restrict my variable to be real and non-negative (i.e k>=0), I am getting the usual message that "Solutions may have being lost". Can somebody please help me on how i can handle this ? Thanks

alpha*beta*(1-alpha)*k^(alpha-1)/(1+beta)-1-(2*alpha-1)*alpha*(1-alpha)*beta*k^(2*(alpha-1))/(1+beta)+alpha^2*k^(alpha-1)

## plotting a series of numbers...

hello maple support,what is the best way to solve for multiple numbers, ie the equation isx/x+1 i can plot it but i want to solve for .5.9.99.999 and 1.5,1.1,1.01 and 1.001.i have tried a number of ways and browsed tutorials on you tube and some pdfs.it is time for help on solving for multiple quantities.thanks,craig

## An error with "simplify"-function that migrates...

by: Maple 17

Try to run the following:

>restart;
>d := conjugate(u)*conjugate(y)+conjugate(v)*conjugate(x);
>z := conjugate(f)/d+conjugate(G)*w*conjugate(w)*conjugate(y)/d;
>z2 := simplify(z);

and you will get correct answer

_        _   _ _

## Change of axis by matrixplot...

Good afternoon everybody,

I have a question regarding the command matrixplot. I wrote a programm with two input parameters:

v=[seq(0.29+i/100,i=1..8)]

k=[seq(2*i,i=1..50)]*0.5*10^(-15)

and I get a matrix [8x50] that I want plot.

The problem with matrixplot is that I get in the axis the number of rows and columns but I would like to put the value of v and k instead of the row/column's number. Someone knows how I can change that?

## two different answers just like a bug for operator...

Dear,i meet a problem in Physics package.i can't find why i got two different answers.

restart; with(Physics); Setup(mathematicalnotation = true);Setup(op = {C});

Cp := Dagger(C);

alg := %Commutator(Cp, C) = -1;

Setup(alg)

S := sqrt(N-(Dagger(C)+sqrt(N)*conjugate(eta))*(C+sqrt(N)*eta)):

eq1 := collect(expand(op(1, S)), N):

xi = op(1, eq1);

f := map(simplify, map(proc (x) options operator, arrow; x*sqrt(xi) end proc, convert...

## Add duplicates in sparse Matrices...

Hello,

I have a small Finite Element program in Maple. I want to accelerate the Matrix assembly. For Matlab this works like described here (http://milamin.sourceforge.net/technical-notes/sparse-matrix-assembly) under "Triplet Sparse Storage". There, two indexing Vectors are used to place the values into a sparse Matrix with the Matlab function sparse. If index pairs are duplicate, they are added.

Now I want to ask if this is also possible in Maple?...

## Remove same (sepcific) elements from Vectors...

Hi all,

Say i have two Vectors:

V1:=Vector(2,[a,b]);

V2:=Vector(4,[d,b,e,a]);

and how do I get

V3:=Vector([d,e]);

?? I currectly use a crude way using 'set' operations:

V3:=convert(V2,set) minus convert(V1,set);

V3:=convert(V3,Vector); # Does not work straightford, so

V3:=convert(V3,list):
V3:=convert(V3,Vector); # Which works,

Also, is there a strightforward way to which elements are the same and their indices?

 First 51 52 53 54 55 56 57 Page 53 of 57
﻿