Correction of Manifolds 1.5 : Manifolds with BoundaryFematika2026-09-18 | Correction of Manifolds 1.5 : Manifolds with BoundarySolving a Combinatorics Problem with Group and Number TheoryFematika2021-07-07 | In this video, I use a group action, Burnside's lemma, Stirling numbers of the first kind, and the rising factorial to prove the number of ways to create an unordered string drawing from an alphabet with replacement.
00:00 Intro 00:35 Explaining the problem 02:44 Introducing permutations 04:40 Cycle notation 06:40 Group action 08:12 Orbits 09:30 Fixed points 10:20 Burnside's Lemma 11:37 Number of fixed points for a permutation 15:12 Stirling Numbers of the first kind 16:32 Stirling number identity 20:28 Examples of Stirling polynomials 23:50 Rising factorial identity proof 28:14 Final answer
Translate This Video : Notes : None yet Patreon : patreon.com/user?u=16481182 Teespring : teespring.com/stores/fematika Email : fematikaqna@gmail.com Discord: discord.gg/5z7pgj5 Subreddit : reddit.com/r/fematika Code : github.com/Fematika/AnimationsAlgebraic Topology 1.5 : Covering Maps and the Fundamental Group of the CircleFematika2020-03-21 | In this video, I introduce what covering maps are, their property of lifting maps, the construction of unique lifts of paths, and then prove that the fundamental group of the circle is isomorphic to the integers using those lifts.
Translate This Video : Notes : None yet Patreon : patreon.com/user?u=16481182 Teespring : teespring.com/stores/fematika Email : fematikaqna@gmail.com Discord: discord.gg/5z7pgj5 Subreddit : reddit.com/r/fematika Code : github.com/Fematika/AnimationsAlgebraic Topology 1.4 : Fundamental GroupFematika2020-03-17 | In this video, I introduce the fundamental group, and explain the induced isomorphism resulting from a path and the induced homomorphism resulting from a continuous map, proving functorality. I also briefly cover retractions and how their induced homomorphism is surjective.
Translate This Video : Notes : None yet Patreon : patreon.com/user?u=16481182 Teespring : teespring.com/stores/fematika Email : fematikaqna@gmail.com Discord: discord.gg/5z7pgj5 Subreddit : reddit.com/r/fematika Code : github.com/Fematika/AnimationsAlgebraic Topology 1.3 : Path Homotopy and Product (Animation Included)Fematika2019-10-20 | In this video, I introduce the concept of path homotopy, as well as the product of paths. This is in build-up to the fundamental group. I talk about the line homotopy, convex sets, and general theorems regarding products of paths and homotopy.
In this video, I will be doing the sum of 17/(75*76) + 17*18/(75*76*77) + 17*18*19/(75*76*77*78), question nineteen from a mathematics competition from Hong Kong.
6:09 - The actual formula for the sum in general 12:34 - The general theorem I will prove (partial sum formula) 23:36 - The infinite sum formula 25:05 - The solution
Translate This Video : Notes : http://www.math.cmu.edu/~cnewstea/notes/algtop-mayervietoris.pdf Patreon : patreon.com/user?u=16481182 Teespring : teespring.com/stores/fematika Email : fematikaqna@gmail.com Discord: discord.gg/5z7pgj5 Subreddit : reddit.com/r/fematika Code : github.com/Fematika/AnimationsCategory Theory and Competition Projective Geometry | Cross TeachingFematika2019-06-15 | Patreon : patreon.com/user/FematikaCategory Theory and Competition Projective Geometry with Essentials of Math | Cross TeachingFematika2019-06-14 | In this video, Essentials of Math will be introducing Projective Geometry as it relates to competition math, and I will introduce the basics of Category Theory. Note that the quality of the video is poor up until around 59:00. This is also unedited, I recommend watching my actual series on Category Theory.
Translate This Video : Notes : None yet Patreon : patreon.com/user?u=16481182 Teespring : teespring.com/stores/fematika Email : fematikaqna@gmail.com Discord: discord.gg/5z7pgj5 Subreddit : reddit.com/r/fematika Code : github.com/Fematika/AnimationsCategory Theory 1.5 : Properties of Functors, Contravariant Functors, and SubcategoriesFematika2019-02-11 | In this video, I introduce the components of a functor and the hom-set functor on locally-small categories. I then prove that isomorphisms preserve monics, epics, initial objects, and terminal objects. I then introduce contravariant functors, and prove that they reverse the aforementioned properties. I then introduce subcategories, the inclusion functor, and how that defines full subcategories.
Email : fematikaqna@gmail.com Discord: discord.gg/ePatnjV Subreddit : reddit.com/r/fematika Code : github.com/Fematika/Animations Notes : docdro.id/7CsGGpxTopology 1.7 : More Examples of TopologiesFematika2018-08-16 | In this video, I introduce important examples of topologies I didn't get the chance to get to. This includes The discrete and trivial topologies, subspace topology, the lower-bound and K topologies on the reals, the dictionary order, and the line with two origins. I also introduce (again) what a Hausdorff topology is.
Email : fematikaqna@gmail.com Discord: discord.gg/ePatnjV Subreddit : reddit.com/r/fematika Code : github.com/Fematika/Animations Notes : None yetManifolds 3.1 : Partitions of Unity on Smooth ManifoldsFematika2018-07-20 | In this video, I introduce partitions of unity and smooth bump functions, and prove that every open cover of a smooth manifold has a partition of unity subordinate to it.
Email : fematikaqna@gmail.com Subreddit : reddit.com/r/fematika Code : github.com/Fematika/Animations Notes : None yetAbstract Algebra 1.6 : Subgroups, Lagranges Theorem, and the CenterFematika2018-06-22 | In this video, I introduce Lagranges theorem, using it and other facts to prove many things about groups and their subgroups. I then introduce the center of a group and use it to prove that groups of order prime squared (|G| = p^2) are abelian.
Email : fematikaqna@gmail.com Subreddit : reddit.com/r/fematika Code : github.com/Fematika/Animations Notes : None yetTopology 1.6 : Metric TopologyFematika2018-06-19 | In this video, I introduce the metric topology, and introduce how the topologies it generates align with the standard topologies on Euclidean space.
Email : fematikaqna@gmail.com Subreddit : reddit.com/r/fematika Code : github.com/Fematika/Animations Notes : None yetSoo...um...*click*...okayFematika2018-06-18 | Sooooo...so now, umm... okay.Manifolds 2.3 : Smooth Maps and DiffeomorphismsFematika2018-06-14 | In this video, I introduce examples and properties of smooth maps, and show the invariance theorems for diffeomorphisms.
Email : fematikaqna@gmail.com Code : github.com/Fematika/Animations Notes : None yet Playlist :de Rham Cohomology | Wrap It Up!Fematika2018-06-12 | In this video, I give a summary of what you need to know to understand the de Rham Cohomolgy.
Email : fematikaqna@gmail.com Code : github.com/Fematika/Animations Notes : None yet Playlist :Ask Me Math! 11Fematika2018-06-11 | I will be answering any all math questions.Set Theory 1.2 : OrdinalsFematika2018-06-08 | In this video, I introduce the Von Neumann construction of the ordinals, including ones that are infinite/transfinite!
Email : fematikaqna@gmail.com Subreddit : reddt.com/r/Fematika Code : github.com/Fematika/Animations Notes : None yetMeasure Theory 2.4 : Sets of Measure ZeroFematika2018-05-14 | In this video, I introduce the Cantor Set, and prove that it and countable sets (including the rationals) have measure zero.
Email : fematikaqna@gmail.com Subreddit : reddit.com/r/fematika Code : github.com/Fematika/Animations Notes : None yetAbstract Algebra 1.5 : Examples of GroupsFematika2018-05-08 | In this video, I introduce many important examples of groups. This includes the group of (rigid) motions, orthogonal group, special orthogonal group, the dihedral groups, and the "finite cyclic group" Z/nZ (or Z_n).
Email : fematikaqna@gmail.com Code : github.com/Fematika/Animations Notes : None yetMy NotebooksFematika2018-05-06 | I go through my notebooks in which I learned math, and discuss some odd stories that went along with them.Topology 1.5 : Order TopologyFematika2018-04-29 | In this video, I introduce the order topology and prove that it is Hausdorff.
Email : fematikaqna@gmail.com Code : github.com/Fematika/Animations Notes : None yetThe Laplacian in Different CoordinatesFematika2018-04-23 | In this video, I derive the coordinate representation of the laplacian in general coordinate systems.