### various bugs

Publié :

**jeu. juil. 27, 2017 11:07 pm**Hi Bernard,

I've noticed few bugs in the current version of Xcas (stable branch), which are listed below.

1. When I try to solve limit in Example 61 in http://math.cmu.edu/~bkell/lhopital.pdf using the commandI get the result 0. But this is wrong, as the correct result should be 16a/9 (which is given by Maxima, for example).

2. The function "plotarea" does not work for straight lines. When I enter, for example, plotarea(x,x=1..2), i get the following error message.
3. When I type I get the correct answer %{NULL%}, i.e. the empty set. But when I type I get a set containing 1, which is incorrect (the above sets should be equal).

4. The function "plotinequation" sometimes does not fill the resulting area although it is expected to do so. For example, a circle will be filled only if its radius is not an integer. The command works fine, but the command only outlines the solution.

5. The unit prefix "micro" is not working.

6. (This is maybe not a bug). When I define F:=Int(x^2,x), I get integral of x^2, as expected ("Int" is an inert function). But when F is part of some subsequent command, the integral gets evaluated, for example when I try to do variable substitution with "subs". It would be nice to get unevaluated integral to show the result of the substitution. Is it possible somehow?

I've noticed few bugs in the current version of Xcas (stable branch), which are listed below.

1. When I try to solve limit in Example 61 in http://math.cmu.edu/~bkell/lhopital.pdf using the command

Code : Tout sélectionner

`assume(a>0); limit((sqrt(2*a^3*x-x^4)-a*root(3,a^2*x))/(a-root(4,a*x^3)),x=a)`

2. The function "plotarea" does not work for straight lines. When I enter, for example, plotarea(x,x=1..2), i get the following error message.

Code : Tout sélectionner

```
"Project-Id-Version: giac 0.9.0
Report-Msgid-Bugs-To:
POT-Creation-Date: 2017-07-17 11:09+0200
PO-Revision-Date: 2010-06-30 10:24+0200
Last-Translator: parisse <bernard.parisse@ujf-grenoble.fr>
Language-Team: English
Language:
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Plural-Forms: nplurals=2; plural=(n != 1);
Error: Bad Argument Value"
```

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`%{1,2,3%} minus %{1,2,3%}`

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`%{cos(k*pi/6-pi/3)$(k=1..100)%} minus %{cos(k*pi/6+pi/3)$(k=1..100)%}`

4. The function "plotinequation" sometimes does not fill the resulting area although it is expected to do so. For example, a circle will be filled only if its radius is not an integer. The command

Code : Tout sélectionner

`plotinequation(x^2+y^2<=3)`

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`plotinequation(x^2+y^2<=4)`

5. The unit prefix "micro" is not working.

6. (This is maybe not a bug). When I define F:=Int(x^2,x), I get integral of x^2, as expected ("Int" is an inert function). But when F is part of some subsequent command, the integral gets evaluated, for example when I try to do variable substitution with "subs". It would be nice to get unevaluated integral to show the result of the substitution. Is it possible somehow?