## how to solve problem...

RootOf(_Z^2*beta*h[1]-alpha*l[1]*l[2], label = _L2)

## Derivative with numerical method...

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Using numerical methods, I cannot calculate the derivative of sd with respect to r at r = 2 and t = 4.

Oliveira.

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## Dirichlet conditions and Neumann values...

Does anyone know how to enter in the pdsolve function Dirichlet conditions and Neumann values?

Oliveira.

## how to display the time in standard format...

I am reading the help page for "time" and it says that it will display the time elapsed since the maple kernel was loaded, but I just want output that is the value of the time and date displayed on my computer at the point the input in the command line is exrcuted. How do I do this?

## Combining solve and plot commands...

Hi,

I am struggling with one task involving solve and plot commands. I would appreciate if I could get some help. What I need to do is as follows:

1. Define alpha between 0 and 1.

2. Solve an equation f(x,alpha) =0 for x by taking different values of alpha.

3. Of all values of x obtained in step 2, choose the value of x between 0 and 1 and discard all others. I have technically shown that there will be exactly one value that is acceptable and all other values of x can be discarded.

4. For different values of alpha and correspondingly selected values of x in step 3, plot and display function g(x,alpha) with function value on the vertical axis and alpha on the horizontal axis.

Regards,

Omkar

## Why is this an error?...

solve({-infinity < a , a < -1, -1 < b ,  b < 0});

## Seeking for a question about a bouncing ball....

Hi,

does anyone remember of a recent question (maybe a post) about a bouncing ball over a hilly ground?
I can't put the finger on it.

TIA

## Why is this piecewise plot giving an error? Pls he...

f(x) := piecewise(0 < x, x^(3/2)*sin(1/x), x = 0, 0, undefined);
plot(f(x));

gives me the following error:

Error, (in plot) incorrect first argument piecewise(0 < x, (HFloat(2.739493386336394e-116)+HFloat(2.739493386336394e-116)*I)*x^(3/2), x = 0, 0, undefined)

I just want to see the function plot. With Wolfram Alpha this is no deal at all!

## How do I plot a function under some constrainets...

I used the implicit function to draw two images, how to display only the intersection of two images? Or, how do I draw the x^2+y^2+z^2=1 image under x+y+z=0 condition? Code show as above.Thank you.

## use of subs with the "``" symbols...

Is it because I have handed subs a multiset or is it because I used the "``" things in the code producing my set? I seemed to remember algsubs and subs working perfectly well regardless of the dimensions of the argument in previous times i have needed it.

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## dsolve returns signular solution which can be obta...

Why Maple returns -1/x as singular solution below when this solution can be obtained from the general solution when constant of integration is zero?

 > restart;
 > ode:=2*y(x)+2*x*y(x)^2+(2*x+2*x^2*y(x))*diff(y(x),x) = 0; dsolve(ode,singsol=false);

 > sol:=[dsolve(ode,singsol=essential)];

 > subs(_C1=0,sol)

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## Sequence of sequence on separate lines...

How can I get a seq(seq(...))) to print each sub-sequence per line? It currently prints all the sequences as one big sequence. I'd like some way to tell it to "eol".

## Loop two outputs...

I've made this proc and it has 2 outputs

*

How do I fix that?

## Perm (object) and its arguments...

Some mathematical functions and also some (not so) inert functions are implemented as objects.
For example, Perm is used to represent permutations.

p :=Perm([2,3,1,5,4]);  # ==> disjoint cycles representation
p:=(1,2,3)(4,5);
lprint(p);
Perm([[1, 2, 3], [4, 5]])

Perm acts as an inert function (like RootOf) but it's an object.
Is it possible to convert it into a true inert form such as PERM([[1, 2, 3], [4, 5]]) and so, being able to extract the arguments with op?

In this specific case we may use
convert(p, disjcyc);
[[1, 2, 3], [4, 5]]

but this is possible only because Perm has a convert export.
So, is it possible to obtain the arguments directly (without convert)?
This would be useful for other situations.