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    <description>RSS Feed for Wolfram Community showing any discussions tagged with Mathematics sorted by active.</description>
    <items>
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        <rdf:li rdf:resource="https://community.wolfram.com/groups/-/m/t/3695977" />
        <rdf:li rdf:resource="https://community.wolfram.com/groups/-/m/t/3695968" />
        <rdf:li rdf:resource="https://community.wolfram.com/groups/-/m/t/3696227" />
        <rdf:li rdf:resource="https://community.wolfram.com/groups/-/m/t/3694198" />
        <rdf:li rdf:resource="https://community.wolfram.com/groups/-/m/t/3694082" />
        <rdf:li rdf:resource="https://community.wolfram.com/groups/-/m/t/3694145" />
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        <rdf:li rdf:resource="https://community.wolfram.com/groups/-/m/t/3690751" />
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        <rdf:li rdf:resource="https://community.wolfram.com/groups/-/m/t/3690586" />
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        <rdf:li rdf:resource="https://community.wolfram.com/groups/-/m/t/3682367" />
        <rdf:li rdf:resource="https://community.wolfram.com/groups/-/m/t/3686348" />
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  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3695977">
    <title>Negative-pedal surface of an elliptic cylinder</title>
    <link>https://community.wolfram.com/groups/-/m/t/3695977</link>
    <description>Find the parametric equations of the negative-pedal surface of the elliptic cylinder:&#xD;
{3 Cos[u], 2 Sin[u], v} with respect to the origin.&#xD;
&#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/501cac52-398a-421b-b27f-853b3054993a</description>
    <dc:creator>Alejandro Latorre Chirot</dc:creator>
    <dc:date>2026-04-18T20:07:43Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3695968">
    <title>Case 3 of the properties of Taylor&amp;#039;s circumferences</title>
    <link>https://community.wolfram.com/groups/-/m/t/3695968</link>
    <description>In this notebook we will see the third property of the points of &#xD;
Taylor&amp;#039;s circumference, the three circles that each pass through the vertex of the triangle and through the foot of each perpendicular to each of the  feet of the heights that are on the sides that form the same vertex. &#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/c1a96910-2d04-40e6-9c82-475fbb34249f</description>
    <dc:creator>Alejandro Latorre Chirot</dc:creator>
    <dc:date>2026-04-18T18:53:27Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3696227">
    <title>For what value of x is the equation below valid?</title>
    <link>https://community.wolfram.com/groups/-/m/t/3696227</link>
    <description>$\left[ \left( (i!)^{\cos(x!) + \sin(i!)} \right)! \right]^i = \phi^{\phi!}$</description>
    <dc:creator>Dagaga Addisu</dc:creator>
    <dc:date>2026-04-18T16:59:48Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3694198">
    <title>All elementary functions from a single binary operator</title>
    <link>https://community.wolfram.com/groups/-/m/t/3694198</link>
    <description>![All elementary functions from a single binary operator][1]&#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][2]&#xD;
&#xD;
&#xD;
  [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Allelementaryfunctionsfromasinglebinaryoperator.png&amp;amp;userId=20103&#xD;
  [2]: https://www.wolframcloud.com/obj/f9491e4a-5414-4fce-89f3-f455dbd662a1</description>
    <dc:creator>Andrzej Odrzywolek</dc:creator>
    <dc:date>2026-04-17T21:05:07Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3694082">
    <title>Pedal, Negative-pedal surfaces and curves of Plücker conoid</title>
    <link>https://community.wolfram.com/groups/-/m/t/3694082</link>
    <description>Find the parametric equations of the pedal and negative-pedal surfaces of the Plücker conoid:&#xD;
{0, 0, Sin[2 u]} + v {Cos[u], Sin[u], 0} with respect to the origin.&#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/8dfbede9-40c6-4e29-9457-14e8e14497c9</description>
    <dc:creator>Alejandro Latorre Chirot</dc:creator>
    <dc:date>2026-04-17T15:29:15Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3694145">
    <title>Case 2 of the properties of the Taylor&amp;#039;s circles</title>
    <link>https://community.wolfram.com/groups/-/m/t/3694145</link>
    <description>In this notebook we will see the second property of the points of Taylor&amp;#039;s circumference, the three circles  that pass each by two feet of the heights of two sides that form a vertex of the triangle and by the feet of two of the perpendicular to these two feet of the heigts that are on the sides that form the same vertex.&#xD;
&#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/f36bc52d-7584-43e6-9696-47089e8e099c</description>
    <dc:creator>Alejandro Latorre Chirot</dc:creator>
    <dc:date>2026-04-17T14:00:41Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3690608">
    <title>New paper shows generation of all elementary functions from a single binary operator</title>
    <link>https://community.wolfram.com/groups/-/m/t/3690608</link>
    <description>I came across this paper (https://arxiv.org/pdf/2603.21852) published this month by Andrzej Odrzywolek and have not been able to stop thinking about it. The claim is that a single binary operator, $\text{eml}(x, y) = \exp(x) - \ln(y)$, paired with the constant 1, generates every elementary function. NAND gates do this for Boolean logic, but continuous math has never had an equivalent, and the standard reduction via Euler and Liouville bottoms out at exp, log, and arithmetic. Odrzywołek shows that the bottom is lower. So $e^x = \text{eml}(x, 1)$, $\ln x = \text{eml}(1, \text{eml}(\text{eml}(1, x), 1))$, and every elementary formula becomes a binary tree over the grammar $S \to 1 \mid \text{eml}(S, S)$.</description>
    <dc:creator>Alisson Silva</dc:creator>
    <dc:date>2026-04-16T11:23:02Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3690751">
    <title>Mathematical Games: space groups and filling space</title>
    <link>https://community.wolfram.com/groups/-/m/t/3690751</link>
    <description>![Mathematical Games: space groups and filling space][1]&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][2]&#xD;
&#xD;
&#xD;
  [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=SpaceGroupsandFillingSpace.png&amp;amp;userId=20103&#xD;
  [2]: https://www.wolframcloud.com/obj/fb4a4c54-b4d7-4f9b-a93a-21427316f9c5</description>
    <dc:creator>Ed Pegg</dc:creator>
    <dc:date>2026-04-16T15:57:25Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3690624">
    <title>Case 1 of Taylor&amp;#039;s Circumferences</title>
    <link>https://community.wolfram.com/groups/-/m/t/3690624</link>
    <description>Taylor&amp;#039;s circumference is a particular case of Tucker&amp;#039;s circles. Taylor&amp;#039;s circumference is that passes through the feet of the perpendiculars drawn from the feet of the heights of the sides of the triangle. In this notebook we will see the first property of the points of Taylor&amp;#039;s circumference, the three circles that pass through each vertex of the triangle and by the foot of a height on the opposite side to the vertex and by the feet of the perpendiculars to that foot of the height on the other two sides of the triangle.&#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/116f7210-d949-476e-bcc9-f9ad2d752392</description>
    <dc:creator>Alejandro Latorre Chirot</dc:creator>
    <dc:date>2026-04-16T14:01:27Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3688956">
    <title>How can I plot the angle value between two 3D vectors</title>
    <link>https://community.wolfram.com/groups/-/m/t/3688956</link>
    <description>I have two vectors, v1 and v2.  I can plot them and calculate the angle between them without any problem.  I would like to plot this angle (theta) between them on my plot.&#xD;
&#xD;
I know that I could draw an arc between the two vectors with a small radius to show an angle measurement, but I am unsure how I can navigate the new plane defined by the two vectors.&#xD;
&#xD;
Any suggestions as to how I could do this?  My work is attached.&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/13054823-0185-4140-84b6-39167a6c4f2d</description>
    <dc:creator>Patrick McMullen</dc:creator>
    <dc:date>2026-04-15T21:45:09Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3690586">
    <title>Critical exponents of the 3D Ising universality class as exact rationals from a Gamma-funct algebra</title>
    <link>https://community.wolfram.com/groups/-/m/t/3690586</link>
    <description>Hello Wolfram Community,&#xD;
&#xD;
I want to share a computational observation that I have not seen discussed in &#xD;
this precise form, and I would genuinely welcome input on whether there is an &#xD;
obvious derivation I am missing.&#xD;
&#xD;
## The observation&#xD;
&#xD;
Consider the coefficient:&#xD;
&#xD;
    Gcurvature[d_] := Gamma[1 + d]^2 / Gamma[1 + 2 d]&#xD;
&#xD;
For integer arguments, this equals `1/Binomial[2n, n]` &amp;#x2014; the reciprocal of the &#xD;
central binomial coefficients. The first few values:&#xD;
&#xD;
    Gcurvature(1) = 1/2,  Gcurvature(2) = 1/6,  Gcurvature(3) = 1/20, Gcurvature(4) = 1/70&#xD;
&#xD;
I have observed that the critical exponents of the three-dimensional Ising &#xD;
universality class appear to be expressible as exact rationals built from these &#xD;
four coefficients.&#xD;
&#xD;
## The three main expressions&#xD;
&#xD;
    eta3D  = Gcurvature[3]^3 / (Gcurvature[1]^3 * Gcurvature[2]^2)       = 9/250       = 0.0360&#xD;
    nu3D   = Gcurvature[3]^3 / (Gcurvature[1] * Gcurvature[2]^2 * Gcurvature[4])  = 63/100      = 0.6300&#xD;
    beta3D = Gcurvature[4]^2 / (Gcurvature[1]^2 * Gcurvature[3]^2)       = 16/49       = 0.326531...&#xD;
&#xD;
The numerator of `nu3D` simplifies remarkably: `5040/8000 = 7!/20^3`.&#xD;
&#xD;
## Comparison with the conformal bootstrap&#xD;
&#xD;
The state-of-the-art values from Chester et al. (2024, arXiv:2411.15300) are:&#xD;
&#xD;
    eta    = 0.0362976(5)    &amp;#x2014; GOD prediction 9/250    &amp;#x2014; error 0.82%&#xD;
    nu     = 0.6299710(4)    &amp;#x2014; GOD prediction 63/100   &amp;#x2014; error 0.005%&#xD;
    beta   = 0.3264187(6)    &amp;#x2014; GOD prediction 16/49    &amp;#x2014; error 0.034%&#xD;
&#xD;
By standard scaling relations, the remaining exponents also become exact rationals:&#xD;
&#xD;
    gamma = 30933/25000  (bootstrap: 1.237076,  error 0.020%)&#xD;
    alpha = 11/100       (bootstrap: 0.110087,  error 0.079%)&#xD;
    delta = 1241/259     (bootstrap: 4.789843,  error 0.035%)&#xD;
&#xD;
## The 2D case is exact&#xD;
&#xD;
For the 2D Ising model (Onsager 1944), the same framework gives exact results:&#xD;
&#xD;
    eta_2D  = Gcurvature[1]^2 = 1/4    (Onsager: 1/4)   EXACT&#xD;
    nu_2D   = Gcurvature[0]   = 1      (Onsager: 1)     EXACT&#xD;
    beta_2D = Gcurvature[1]^3 = 1/8    (Onsager: 1/8)   EXACT&#xD;
&#xD;
Mean-field values (d &amp;gt;= 4) also match exactly:&#xD;
&#xD;
    eta_MF  = 0        EXACT&#xD;
    nu_MF   = Gcurvature[1] = 1/2    EXACT&#xD;
    beta_MF = Gcurvature[1] = 1/2    EXACT&#xD;
&#xD;
## Context&#xD;
&#xD;
This observation forms part of a broader framework I have been developing &#xD;
(GOD Theory, DOI: 10.5281/zenodo.19599917), in which these coefficients &#xD;
arise as curvature coefficients of a fractal algebra built on fractional &#xD;
derivatives. However, the numerical match above holds independently of that &#xD;
framework and can be verified by anyone with the attached notebook.&#xD;
&#xD;
## What I am asking&#xD;
&#xD;
The 2D Ising match and the mean-field match are exact. The 3D match is &#xD;
empirical at the 0.005%-0.82% level. I do not have a rigorous derivation &#xD;
of the exponent patterns (why specifically `Gcurvature[3]^3 / (Gcurvature[1]^3 * Gcurvature[2]^2)` &#xD;
for eta, for example). &#xD;
&#xD;
My question to the Community: does anyone see an obvious path to this via &#xD;
the renormalisation group, conformal field theory, or the structure of &#xD;
central binomial coefficients? Has any similar pattern been observed?&#xD;
&#xD;
The attached notebook contains all computations in roughly 30 lines of &#xD;
Wolfram Language. Please feel free to run it, criticize it, or extend it.&#xD;
&#xD;
Thanks in advance.&#xD;
&#xD;
Francisco Torrado Cano&#xD;
Independent Researcher&#xD;
Cáceres, Spain</description>
    <dc:creator>Francisco Torrado Cano</dc:creator>
    <dc:date>2026-04-16T11:00:14Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3690123">
    <title>A brief introduction to linear programming in The Wolfram Language</title>
    <link>https://community.wolfram.com/groups/-/m/t/3690123</link>
    <description>&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/f7fbd8d8-56c6-4e84-9db6-cbab093d58c5</description>
    <dc:creator>Theo Vine</dc:creator>
    <dc:date>2026-04-16T07:15:42Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3682367">
    <title>Robots dancing randomly: a stage movement probability puzzle</title>
    <link>https://community.wolfram.com/groups/-/m/t/3682367</link>
    <description>![enter image description here][1]&#xD;
&#xD;
&#xD;
For options A, B, C, and D, how to draw visual diagrams for all valid path scenarios that meet the conditions? For each distinct case, draw a detailed diagram, and use these visual illustrations to help understand and solve the problem.&#xD;
&#xD;
    (*Find all valid non-negative integer solutions*)sol = &#xD;
     FindInstance[{x + y + z + w == 4, x - y == -2, w == z, x &amp;gt;= 0, &#xD;
       y &amp;gt;= 0, z &amp;gt;= 0, w &amp;gt;= 0}, {x, y, z, w}, Integers, 10]&#xD;
    &#xD;
    (*Calculate number of paths for each solution*)&#xD;
    paths = 4!/(x! y! z! w!) /. sol&#xD;
    &#xD;
    (*Total number of valid paths*)&#xD;
    total = Total[paths]&#xD;
    &#xD;
    (*Check if option A is correct*)&#xD;
    Print[&amp;#034;Is option A correct? &amp;#034;, total == 12]&#xD;
&#xD;
The above is the computational method I used to verify whether Option A is correct. Now I want to visualize all valid paths for each option using grid diagrams, count the number of paths and calculate the probabilities to determine the correctness of each option. How can I draw such diagrams?&#xD;
&#xD;
  [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=2026-04-11_092228.png&amp;amp;userId=3593842</description>
    <dc:creator>Bill Blair</dc:creator>
    <dc:date>2026-04-11T01:43:23Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3686348">
    <title>Formal symbols in the UD calculus: evaluation control</title>
    <link>https://community.wolfram.com/groups/-/m/t/3686348</link>
    <description>&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/e1aa2b28-96b1-4104-8347-1e38ecdf5e0d</description>
    <dc:creator>Brian Beckman</dc:creator>
    <dc:date>2026-04-14T16:21:26Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3688913">
    <title>Offset surface of a plane</title>
    <link>https://community.wolfram.com/groups/-/m/t/3688913</link>
    <description>An Offset surface, is a smooth surface (without edges, peaks, or singular points, where each point has a tangent plane. Examples: Spheres, ellipsoids,  toroids, cylinders and planes), it is defined as follows:&#xD;
&#xD;
 sd[u, v] = s[u, v]  +  d n[u, v] and  sd[u, v] = s[u, v]  -  d n[u, v]&#xD;
  &#xD;
s[u, v] it is a smooth surface, d = distance, n[u, v] it is the normal unitary  vector to the surface s[u, v].&#xD;
  In this notebook we will obtain the offset surface of the plane: &#xD;
  {-2, 4, 5} + u{4, -4, -6} + v{5, 3, -5} with d = 3.&#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/fb6f7a2c-9212-43d4-902c-fd22f32c8bbe</description>
    <dc:creator>Alejandro Latorre Chirot</dc:creator>
    <dc:date>2026-04-15T19:42:55Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3688732">
    <title>Spacefilling polyhedra: Voronoi cell tessellation &amp;amp; stereohedra classification in 3D Euclidean space</title>
    <link>https://community.wolfram.com/groups/-/m/t/3688732</link>
    <description>&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/5a7894fc-4cd0-439f-9d83-25d28bb47b37</description>
    <dc:creator>Ed Pegg</dc:creator>
    <dc:date>2026-04-15T15:43:34Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3688820">
    <title>Offset surface of a cylinder</title>
    <link>https://community.wolfram.com/groups/-/m/t/3688820</link>
    <description>An Offset surface, is a smooth surface (without edges, peaks, or singular points, where each point has a tangent plane. Examples: Spheres, ellipsoids, toroids, cylinders and planes), it is defined as follows:&#xD;
&#xD;
 sd[u, v] = s[u,v] + d n[u, v] and  sd[u, v] = s[u,v] - d n[u, v]&#xD;
  &#xD;
 s[u, v] it is a smooth surface, d = distance, n[u, v] it is the normal unitary &#xD;
  vector to the surfaces[u, v].&#xD;
  In this notebook we will obtain the offset surface of the cylinder: &#xD;
&#xD;
  {Cos[u],Sin[u],v} with d = 1.5.&#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/88b265ae-7b15-4b35-aedd-0301a3453cc5</description>
    <dc:creator>Alejandro Latorre Chirot</dc:creator>
    <dc:date>2026-04-15T15:29:44Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3688629">
    <title>Adams circumference</title>
    <link>https://community.wolfram.com/groups/-/m/t/3688629</link>
    <description>It is the circle that has the center to the incenter. To obtain ii first we will calculate the tangent points of the inscribed circumference and we will trace the Gergonne triangle which is what passes through those points. Then we will get the Gergonne point of the base triangle. By the Gergonne point we draw a parallel line to one side of the Gergonne triangle and we will obtain one of the points through which the Adams circumference passes. We will calculate the radius at that point and the center. &#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/ea497de1-cadd-4a10-9590-23b9e8a7ae73</description>
    <dc:creator>Alejandro Latorre Chirot</dc:creator>
    <dc:date>2026-04-15T14:52:46Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3686271">
    <title>Offset surface of a toroid</title>
    <link>https://community.wolfram.com/groups/-/m/t/3686271</link>
    <description>An Offset surface, is a smooth surface (without edges, peaks, or singular points, where each point has a tangent plane. Examples: Spheres, ellipsoids, toroids, cylinders and planes), it is defined as follows:&#xD;
&#xD;
 sd[u, v] =s[u, v] + d n[u, v] and sd[u, v] =s[u, v] - d n[u, v]&#xD;
  &#xD;
  s[u, v] it is a smooth surface, d = distance, n[u, v] it is the normal unitary vector to the surface s[u, v].&#xD;
  In this notebook we will obtain the offset surface of the toroid: &#xD;
  {(5 + 2 Cos[u])Cos[v], (5 + 2 Cos[u])Sin[v], 2 Sin[u]}   with   d = 1.5.&#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/3930c95f-9d47-4065-8002-d47549c73e75</description>
    <dc:creator>Alejandro Latorre Chirot</dc:creator>
    <dc:date>2026-04-14T17:45:18Z</dc:date>
  </item>
  <item rdf:about="https://community.wolfram.com/groups/-/m/t/3686328">
    <title>Offset surface of a sphere</title>
    <link>https://community.wolfram.com/groups/-/m/t/3686328</link>
    <description>An Offset surface, is a smooth surface (without edges, peaks, or singular points, where each point has a tangent plane. Examples: Spheres, ellipsoids, toroids, cylinders and planes), it is defined as follows:&#xD;
&#xD;
 sd[u, v] = s[u, v] + d n[u, v] and  sd[u, v] = s[u, v] - d n[u, v]&#xD;
  &#xD;
 s[u, v] it is a smooth surface, d = distance, n[u, v] it is the normal unitary vector to the surface s[u, v].&#xD;
  In this notebook we will obtain the offset surface of the sphere: &#xD;
  {3 Cos[u]Cos[v], 3 Sin[u]Cos[v], 3 Sin[v]}   with   d = 2.&#xD;
&#xD;
&#xD;
&amp;amp;[Wolfram Notebook][1]&#xD;
&#xD;
&#xD;
  [1]: https://www.wolframcloud.com/obj/0ca7eedf-b306-449f-8ed2-39ee801127fe</description>
    <dc:creator>Alejandro Latorre Chirot</dc:creator>
    <dc:date>2026-04-14T14:01:10Z</dc:date>
  </item>
</rdf:RDF>

