https://community.wolfram.com RSS Feed for Wolfram Community showing any discussions tagged with Mathematics sorted by new. https://community.wolfram.com/groups/-/m/t/3756631 Limit[(t^2 (-1 + t^k))/(-1 + t), k -> +Infinity] // FullSimplify[#, 0 < t < 1] & The code is not correctly calculating the right limit value, where the parameter t ranges from 0 < t < 1. The correct result should be t²/(1 - t). How can this be obtained? Wen Dao 2026-07-12T02:50:44Z https://community.wolfram.com/groups/-/m/t/3756371 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/b865cc51-dfe0-4120-b064-954f66c0f01c Alejandro Latorre Chirot 2026-07-11T22:34:37Z https://community.wolfram.com/groups/-/m/t/3756327 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/adf6c134-2522-4e40-9530-169a4f560c81 Ed Pegg 2026-07-11T14:29:15Z https://community.wolfram.com/groups/-/m/t/3755693 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/ec23aaee-5ccf-4a58-80f4-89308128cec2 Alejandro Latorre Chirot 2026-07-10T21:43:08Z https://community.wolfram.com/groups/-/m/t/3755908 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/dd61d583-aa72-4df5-b6a1-878009859a83 Alejandro Latorre Chirot 2026-07-10T21:28:09Z https://community.wolfram.com/groups/-/m/t/3755592 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/e827c398-ac5b-4aa9-b68a-54d70a432fd4 Alejandro Latorre Chirot 2026-07-10T16:13:24Z https://community.wolfram.com/groups/-/m/t/3754811 ![Simulate circadian rhythm cycles for unusual sleep schedules][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Screenshot2026-07-09at23.25.33.png&userId=3740488 [2]: https://www.wolframcloud.com/obj/ff1e8b2c-c30c-4d04-b653-87a1e4d69201 Jolie Nguyen 2026-07-10T03:27:33Z https://community.wolfram.com/groups/-/m/t/3754125 ![enter image description here][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Screenshot2026-07-09at7.30.59%E2%80%AFPM.png&userId=3753710 [2]: https://www.wolframcloud.com/obj/5286a4e2-cc4f-4e10-a63c-53f17625aec7 Warren Chen 2026-07-10T00:58:00Z https://community.wolfram.com/groups/-/m/t/3753019 ![enter image description here][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=newPunch.png&userId=3751686 [2]: https://www.wolframcloud.com/obj/nicholaszhan1/Published/Analysing%20the%20Rotational%20Kinetic%20Chain%20of%20a%20Cross%20Punch.nb Nicholas Zhan 2026-07-09T21:41:31Z https://community.wolfram.com/groups/-/m/t/3752071 ![image][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Screenshot2026-07-09at4.33.15%E2%80%AFPM.png&userId=3740316 [2]: https://www.wolframcloud.com/obj/bbf6661d-dc8c-4d9d-b452-28004d2dd42c Saanvi Raghavendran 2026-07-09T21:05:57Z https://community.wolfram.com/groups/-/m/t/3752149 ![Spectral universality of deficit-angle curvature in Regge Laplace-Beltrami geometry][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=WSRPThumbnailProject.png&userId=3749899 [2]: https://www.wolframcloud.com/obj/8ff2c8d8-86c9-425c-89a2-3a8149cd0881 Arnav Mittal 2026-07-09T20:38:24Z https://community.wolfram.com/groups/-/m/t/3739392 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/c3fad79c-0458-4901-8177-944b192d22da Robert Rimmer 2026-06-27T01:40:35Z https://community.wolfram.com/groups/-/m/t/3739768 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/1e12df01-334f-4d61-b34f-fce23458d9a6 Marco Thiel 2026-06-26T15:16:21Z https://community.wolfram.com/groups/-/m/t/3738945 ![Periodic family of Jacobi elliptic functions][1] &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=jacobir.gif&userId=610054 [2]: https://www.wolframcloud.com/obj/6fa25f1f-b37f-421c-8150-d883b89e9028 Clayton Shonkwiler 2026-06-24T16:38:04Z https://community.wolfram.com/groups/-/m/t/3736053 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/18003051-8b86-4622-8f54-3a2e360b8aaa Ed Pegg 2026-06-18T15:52:12Z https://community.wolfram.com/groups/-/m/t/3734101 &[Wolfram Notebook][1] [1]: https://www.wolframcloud.com/obj/ecf0ae24-9510-48a9-8ff7-40f451771eaf Naman Taggar 2026-06-15T15:59:55Z https://community.wolfram.com/groups/-/m/t/3732396 ![Discrete differential geometry on meshes via the cotangent Laplacian][1] The whole notebook in one image. A triangle mesh has no curvature, no spectrum, no notion of distance — none of differential geometry — until you build it. The surprise is that a **single sparse matrix, the cotangent Laplacian**, manufactures all of it. Here is the same torus seen four ways through that one operator: its Gaussian **curvature**, its Laplace-Beltrami **vibration modes**, mean-curvature **flow**, and heat-method **geodesic distance**. &[Wolfram Notebook][2] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Video-bf248396-73e0-42b0-994d-2814b8192166-ezgif.com-optimize.gif&userId=20103 [2]: https://www.wolframcloud.com/obj/200b007e-0739-4903-aea6-d66a604addac Marco Thiel 2026-06-12T12:46:06Z https://community.wolfram.com/groups/-/m/t/3730754 f[x_] := E^x /; -2 <= x < 0 f[x_] := f[x - 2] /; x > 0 f[x_] := f[x + 2] /; x < -2 Plot[{f[x], -x/8 + 1/2}, {x, -6, 4}] The graph of the function drawn by the above code is as follows: ![enter image description here][1] The precise and correct graph is as shown in the image below: ![enter image description here][2] ![enter image description here][3] The issues with the graph plotted by the code are mainly as follows: 1. At the boundary points of the piecewise intervals, the graph is not a vertical line segment but rather has no image at all. See the parts circled in red in the figure above. 2. The right endpoint of each interval is not included; the graph should use an open circle at that point to indicate this, as shown by the yellow circles in the figure. However, it does not. How should the code be modified so that the generated graph matches the correct, normal function graph shown above? [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=007.jpg&userId=3593842 [2]: https://community.wolfram.com//c/portal/getImageAttachment?filename=2026-06-10_183157.png&userId=3593842 [3]: https://community.wolfram.com//c/portal/getImageAttachment?filename=7904007.jpg&userId=3593842 Bill Blair 2026-06-10T10:42:44Z https://community.wolfram.com/groups/-/m/t/3730733 Reduce[ForAll[x, 0 < x < \[Pi]/2, 2 a Sin[a x] >= 0], a, Reals] ![enter image description here][1] [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=2026-06-10_074718.png&userId=3593842 Bill Blair 2026-06-09T23:47:41Z https://community.wolfram.com/groups/-/m/t/3729334 I guessed the following area formula for a (planar) quadrilateral using two opposite sides and four angles:(When $a=AB$ and $c=CD$,) $S = \frac{a^2}{2(\cot A + \cot B)} + \frac{c^2}{2(\cot C + \cot D)}$ ![enter image description here][1] This formula can be applied to the quadrilateral satisfying $A+B \ne \pi$ and $C+D \ne \pi$, including convex, concave, and even self-intersecting cases. I'd like to know the applicable case , inapplicable case and reasons for the validity of those cases. Are there any known papers or more elegant ways to derive this formula?I guess there are many ways to explain those reasons. It greatly resembles $S = \frac{1}{2}(ab \sin B + cd \sin D)$. It seems that $b$ and $d$ can be determined using $a, c, A, B, C, D$. [1]: https://community.wolfram.com//c/portal/getImageAttachment?filename=Screenshot2026-06-0811.18.44.png&userId=3725129 Ryo Takayama 2026-06-08T02:26:22Z