## Missing inflection point...

I'm wondering what I'm missing here: with Student[Calculus1]: InflectionPoints(x^(5/3) - 5*x^(2/3),x) returns an empty result where there should be an inflection point at (-1,-4). I suppose there is a real easy solution to this. Please enlighten me. Tim

## Viewing steps of a simplification...

When simplifying an expression or solving an equation, is there a way to have Maple display some of the steps without having to put them in manually?

## generate code for numerical integral...

Is it possible to generate C or Fortran code for a numerically evaluated integral (ie. evalf(Int(...)) )? with(CodeGeneration): and either C(..) or Fortran(...) yield the error message: Warning, the function names {Int} are not recognized in the target language (a similar error message occurs for an int(..) expression) Alejandro

## multiple animations...

A student in my PDE class asked about having two functions in animation at the same time. Here is how I suggested doing this: > f:=(t,x)->sin(t)*x*(1-x); > g:=(t,x)->cos(t)*x*(1-x); > N:=50; > for n from 0 to N do J[n]:=plot([f(2*Pi*n/N,x),g(2*Pi*n/N,x)],x=0..1): od: n:='n': > plots[display]([seq(J[n],n=0..N)],insequence=true); Is there a simpler way? Jim Herod

## Why won't assume and assuming work consistently?...

I am trying to determine when one inequality implies another inequality and I am finding that assume and assuming aren't working consistently for me. I've put the code for my test run below. It seems to work the first time through when I assume mylist[1], but when I assume mylist[2] it always returns false. If I explicitly test is(x>-4) it returns true as it should but if I ask it to determine is(mylist[5]) (which is x>-4 once mylist is overwritten) it returns false? Is there a reason for this? I'm eventually going to need to put it all into a loop that works for any list--is there a way that will guarantee that it will work consistently?

## Why don't these structured types work?...

Why don't these structured types work? > type(Pi, symbol); > evalb(Pi::symbol); > type(Pi, constant); > evalb(Pi::constant); > type(x, symbol); > evalb(x::symbol); > type(x, constant); > evalb(x::constant); > type(Pi, symbol and not constant); > evalb(Pi::(symbol and not constant)); > type(x, symbol and not constant); > evalb(x::(symbol and not constant)); I know we can do it using TypeTools[AddType]( variable, t->evalb(t::symbol and not t::constant) ); but why doesn't the simple version work? Phil

## Maplets/Lists...

How do I extract an element from a list in a Maplet? In Maple, if I wanted the 1st entry in list A, I'd just use A[1]. In a Maplet, the output of a DropDownBox is a list containing a string, but 'DDB'[1] seems to make no sense to the Maplet.

## Relative URL hyperlink within a worksheet...

I want to distribute a collection of Maple-related materials to students or other users. One of the "documents" is a Maple worksheet that contains a hyperlink to other material in the distribution. So, I want to have a URL hyperlink reference to, say, "./web/mystuff.html". It appears to me that Maple's hyperlinks are designed for use only with static, and external, websites. The hyperlink properties popup dialog does not allow me to browse to a local file; I can only browse to a worksheet or maplet. I can get around this limitation by manually editing the worksheet file. I can give an explicit path to the file but I have been unable to find a way to use a relative path to the file.

## Maplet output...

How can I get a Maplet to output a simple real number? What I'm trying to write simply asks for a real number, which will then be used in a worksheet after the Maplet is called. A better question might be, How can I extract a number from a string? Since Maplets appear to output ["123.456"] -- How can I assign the 123.456 to a variable? Thanks, Shannon

## Calculating prime numbers...

Hello, A Maple user sent me a technical support e-mail today with questions about calculating prime numbers, and I thought that it would be worthwhile to post the questions in this forum for our community to answer. The questions are: 1. What is the "best and final" algorithm to find a prime number in Maple? 2. How can you use Maple to calculate the last Mersenne prime number? Bryon Thur Manager, Business Information Systems Maplesoft

## Solutions to sin(x)=sin(1/x)...

When I graph the functions sin(x) and sin(1/x) in maple I can see that these functions will intercept each other an infinite number of times. However, when I write the equation sin(x)=sin(1/x) and click on it and choose solve maple only ruturns the obvious solutions 1 and -1. I can see that sin(1/x) ->0 as x increases (x>2/Pi) and that sin(x) will repeatedly assume all values between 0 and 1 as x increases. In general, how can you find the values where the two functions intercept on some interval where x>1, say [2,10], and also on some interval where x is between 0 and 1? Can I do this with Maple both algebraically and numerically?

## Exporting Maple plots to MS-Word...

You can use export to metafile. The problem is that the created file is not a vector based graphic. So when you print it or when you enlarge it, the pixels appear and deteorate the quality. MATLAB has two options in copying a plot into clipboard: copy as bitmap and copy as metafile. But in Maple the Metafile has not any difference with Bitmap! I do this by exporting my figure to .eps (color or B&W), then importing it from Word. A more complicated task!