<rss version="2.0">
<channel>
<title>MathAction changed pages</title>
<link>https://wiki.fricas.org</link>
<description>MathAction changed pages</description>
<language>en</language>
<pubDate>Fri, 12 Jun 2026 19:19:22 +0000</pubDate>
<item>
<title>[AxiomSources] </title>
<link>https://wiki.fricas.org/AxiomSources</link>
<guid>https://wiki.fricas.org/AxiomSources</guid>
<description>
??changed:
-For up-to-date information about Axiom see http://axiom-developer.org
Axiom is no longer actively developed.  Last version is available as a Debian package.

Copy of old Axiom website is preserved at https://www.nongnu.org/axiom
</description>
<pubDate>Wed, 01 Jul 2026 21:03:43 +0000</pubDate>
</item>
<item>
<title>[FriCAS Library Examples] </title>
<link>https://wiki.fricas.org/FriCASLibraryExamples</link>
<guid>https://wiki.fricas.org/FriCASLibraryExamples</guid>
<description>
??changed:
-   ExampleTrigonometricConstants
  ExampleTrigonometricConstants
</description>
<pubDate>Wed, 01 Jul 2026 20:37:14 +0000</pubDate>
</item>
<item>
<title>[RecurrenceRelationOperator] </title>
<link>https://wiki.fricas.org/RecurrenceRelationOperator</link>
<guid>https://wiki.fricas.org/RecurrenceRelationOperator</guid>
<description>
++added:
RecurrenceOperator is included in FriCAS, content below is kept for historical reasons.

</description>
<pubDate>Wed, 01 Jul 2026 20:13:07 +0000</pubDate>
</item>
<item>
<title>[OtherComputerAlgebraSystems] </title>
<link>https://wiki.fricas.org/OtherComputerAlgebraSystems</link>
<guid>https://wiki.fricas.org/OtherComputerAlgebraSystems</guid>
<description>
++added:
  Sympy -- See: https://sympy.org

Due to size and complexity access to Sage (see: https://sagemath.org) is not feasible.

</description>
<pubDate>Wed, 01 Jul 2026 19:44:08 +0000</pubDate>
</item>
<item>
<title>[BugTracker] </title>
<link>https://wiki.fricas.org/BugTracker</link>
<guid>https://wiki.fricas.org/BugTracker</guid>
<description>
??changed:
-FriCAS bugs should be reported in FriCAS bug tracker at SourceForge:
-http://sourceforge.net/p/fricas/bugs/
FriCAS bugs should be reported in FriCAS bug tracker at Github:
https://github.com/fricas/fricas/issues/
</description>
<pubDate>Mon, 22 Jun 2026 23:01:49 +0000</pubDate>
</item>
<item>
<title>[FriCASIntegration] another silly algebraic case, totally different form from WA</title>
<link>https://wiki.fricas.org/FriCASIntegration</link>
<guid>https://wiki.fricas.org/FriCASIntegration</guid>
<description>
??changed:
-Subject: another silly algebraic case, totally different form from WA
Subject: another silly algebraic case, totally different form from WA (it's not obvious that (t-x)(t+x)=1)
</description>
<pubDate>Thu, 04 Jun 2026 18:27:18 +0000</pubDate>
</item>
<item>
<title>[#218 New version Reduce 3.8 includes MathML] </title>
<link>https://wiki.fricas.org/218NewVersionReduce38IncludesMathML</link>
<guid>https://wiki.fricas.org/218NewVersionReduce38IncludesMathML</guid>
<description>
++added:

From test1 Sun May 31 22:43:59 +0000 2026
From: test1
Date: Sun, 31 May 2026 22:43:59 +0000
Subject: 
Message-ID: &lt;20260531224359+0000@wiki.fricas.org&gt;

Category: Reduce =&gt; MathAction 

</description>
<pubDate>Sun, 31 May 2026 22:43:59 +0000</pubDate>
</item>
<item>
<title>[ExampleTrigonometricConstants] </title>
<link>https://wiki.fricas.org/ExampleTrigonometricConstants</link>
<guid>https://wiki.fricas.org/ExampleTrigonometricConstants</guid>
<description>
??changed:
-
Example of computations with trigonometric constants

Consider the problem:

Let $t := (5/9)\pi$.  Simplify $tan(t) + 4sin(t)$.

We can solve it by noting that involved numbers can be expressed in terms of roots of $1$,  Namely,
first we express trigonometric functions in terms of complex exponentials.  Since $(5/9)\pi$ is
a rational multiple of $\pi$ we get root of $1$, in this case root of degree $18$.  But we also
need $i$, which leads to root of degree $36$. Corresponding field is extention by cyclotomic
polynomial, so we build it:
\begin{axiom}
cyclotomic(36)$CyclotomicUtilities
)set output algebra on
)set output tex off
cF := SAE(FRAC(INT), SUP(FRAC(INT)), %)
)set output tex on
)set output algebra off
\end{axiom}
Now, we can express all ingredients in terms of generator:
\begin{axiom}
et := (generator()$cF)^10
ct := (et + 1/et)/2
st := (et - 1/et)/(2*(generator()$cF)^9)
\end{axiom}
and our expression is:
\begin{axiom}
ex := (4*ct + 1)*st/ct
\end{axiom}
Now we can find minimal polynomial and find its roots:
\begin{axiom}
minimalPolynomial(%)
\end{axiom}
and we see that the result is $\sqrt(3)$.

We could also observe that the expression above is a member of smaller cyclotomic field and from           
that infer expression $2\cos(\pi/6)$.

Consder now expression
$$
i(5\sin((5\pi)/7)-5\sin((4\pi)/7)+5\sin((3\pi)/7) -5\sin((2\pi)/7)) -5\cos((5\pi)/7)+5\cos((4\pi)/7)
$$
$$
-5\cos((3\pi)/7)+5\cos((2\pi)/7) -10\cos(\pi/7)+6.
$$

Now we need root of $1$ of degree $28$, so we build the field:
\begin{axiom}
cyclotomic(28)$CyclotomicUtilities
)set output algebra on
)set output tex off
cF2 := SAE(FRAC(INT), SUP(FRAC(INT)), %)
)set output tex on
)set output algebra off
\end{axiom}

Root of degree $4$ that is generator to power $7$ gives us imaginary unit $i$,  Suare of generator gives
us primitive root of degree $7$, that is $\exp(\pi/7)$:
\begin{axiom}
im2 := generator()$cF2^7
e1 := generator()$cF2^2
\end{axiom}
We express trigonometric functions in terms of this
\begin{axiom}
c1 := (e1 + 1/e1)/2
e2 := e1^2
c2 := (e2 + 1/e2)/2
s2 := (e2 - 1/e2)/(2*im2)
e3 := e1^3
c3 := (e3 + 1/e3)/2
s3 := (e3 - 1/e3)/(2*im2)
e4 := e1^4
c4 := (e4 + 1/e4)/2
s4 := (e4 - 1/e4)/(2*im2)
e5 := e1^5
c5 := (e5 + 1/e5)/2
s5 := (e5 - 1/e5)/(2*im2)
\end{axiom}
Using this we can compute the expression:
\begin{axiom}
im2*(5*s5 - 5*s4 + 5*s3 - 5*s2) - 5*c5 + 5*c4 - 5*c3 + 5*c2 - 10*c1 + 6
\end{axiom}
</description>
<pubDate>Mon, 02 Mar 2026 18:17:05 +0000</pubDate>
</item>
<item>
<title>[ExampleFreeModule] </title>
<link>https://wiki.fricas.org/ExampleFreeModule</link>
<guid>https://wiki.fricas.org/ExampleFreeModule</guid>
<description>
??changed:
-
How to use FreeFreeModule

Commit https://github.com/fricas/fricas/commit/e5785c16bf7552522aac47ab5bb698244bffe090
removed the domain FreeAbelianGroup from FriCAS.

See also
https://groups.google.com/g/fricas-devel/c/yYgfAC-KWhg/m/p23BP5ZSBQAJ .

It can be replaced by FreeModule as follows.

\begin{axiom}
)version
Z ==&gt; Integer
FreeAbelianGroup X ==&gt; FreeModule(Integer,X)
A ==&gt; FreeAbelianGroup(M)
M ==&gt; Matrix Z
m1 := matrix [[1,2],[3,4]]
m2 := matrix [[8,3]]
m3 := matrix [[6],[7]]
a1 := m1::A; a2:=m2::A;a3:=m3::A;
x1 := 2*a1+a2
x2 := 3*a1-5*a3
x1+x2
\end{axiom}

</description>
<pubDate>Fri, 27 Feb 2026 08:25:13 +0000</pubDate>
</item>
<item>
<title>[Symbolic Integration] </title>
<link>https://wiki.fricas.org/SymbolicIntegration</link>
<guid>https://wiki.fricas.org/SymbolicIntegration</guid>
<description>
??changed:
-Unfortunately, due to a bug during final processing this result got mangled and elliptic
-integral part is dropped, giving wrong result.
-
-We gets correct result when we keep only algebraic part

Below is result when we keep only algebraic part
</description>
<pubDate>Wed, 23 Jul 2025 14:26:04 +0000</pubDate>
</item>
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