Re: [Maxima-discuss] Basic simplify question

[Stavros M. <mac...@gm...>]

There are lots of ways to get the result you want manually:

*x*multthru(tst/x) *-- Ray's suggestion

*multthru *only operates on the top level of the expression, so is more
"precise" than *expand*

*substpart(multthru(piece),factor(tst),[1,2])*

this post-processes the result of *factor*

*rembox(factor(substpart(box(piece),tst,1,1)))*

this is essentially Fateman's solution, using *box* instead of variable
substitution

*rembox(factor(substpart(box(piece),tst,1,1,2)))*

more narrowly targeted version of the same

There's also the *format* subsystem, though I'm not very familiar with it.


On Mon, Nov 10, 2025 at 10:31 AM Richard Fateman <fa...@gm...> wrote:

>  I agree with Ray on this. Note that
> factor operates on the rational form of tst, and
> rat(tst) produces
>
> (x*%e^cos(x+1)+x)/%e^cos(x+1)
>
> in essence, the exp(-cos(x+1))     is "simplified"   to  1/ exp(cos(x+1))
> before factoring.
>
> If the user wants exp(-cos(x+1))  to be treated as a single unit, then use
> a symbol,
> like emcosxp1   for manipulation,  at least until such time as some
> property
> related to x  or cos ... is needed.
>
> factor( x* emcosxp1+x)  produces what you might expect.
>
> RJF
>
>
> On Mon, Nov 10, 2025 at 9:02 AM Raymond Toy <toy...@gm...> wrote:
>
>>
>> On 11/10/25 1:35 AM, Gunter Königsmann via Maxima-discuss wrote:
>>
>> Dear all,
>>
>> A colleague of mine has asked me how to factor out the x in
>>
>> tst:x*exp(-cos(x+1))+x;
>>
>> factor(tst) factorizes the exp() function, as well, which doesn't meet my
>> colleague's idea of "simple".
>>
>> He wants the result to be `x*(1+exp(-cos(x+1))`?
>>
>> I thought maybe `factorout` would do this, but it doesn't.
>>
>> I've generally given up on finding ways to make Maxima produce the form I
>> want and just accept what Maxima produces.  If I really, really want a
>> certain form, I just do it by hand.  In this case, do `x*expand(tst/x)`.
>> Sometimes it's just easier to do by hand instead of spending minutes or
>> hours trying to figure out how to get Maxima to do it.  Especially if it's
>> just a one-time change.
>>
>>
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