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Everyone is Bald
This is a well-known joke, so many of you might already be familiar with it. Nonetheless, it’s quite amusing as a joke. 😆 The Assertion: “Everyone is Bald” As indicated in the title, we will prove the assertion that “everyone is bald” using mathematical induction (often simply called induction). Understanding Mathematical Induction Let \( P(n)…
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Convex Set
Definition Let \( K \) be a subset of the \( n \)-dimensional Euclidean space \( \mathbb{R}^n \). When any line segment \( \overline{xy} \) that connects two any points \( x \) and \( y \) in \( K \) is also contained within \( K \), we say that \( K \) is…
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Spherical Harmonics
Laplacian The Laplacian on \(\mathbb{R}^3 \), \[ \Delta = \left( \frac{\partial^2}{\partial x^2},\ \frac{\partial^2}{\partial y^2},\ \frac{\partial^2}{\partial z^2 } \right), \] is a second-order differential operator. When this operator is expressed in spherical polar coordinates in \( \mathbb{R}^3 \), where \[ x = r \sin \theta \cos \varphi,\ y = r \sin \theta \sin\varphi,\ z = r…
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Jordan Curve Theorem
The following theorem is called the Jordan Curve Theorem. Definition Let \( c \) be a loop⭕️ in the plane (also known as a Jordan curve or simple closed curve). The complement of \( c \) in \( \mathbb{R}^2 \), denoted \( \mathbb{R}^2-c \), consists of a bounded domain (the interior) and an unbounded domain…
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Poincaré Conjecture
Simply connected is a fundamental concept in mathematics, particularly in topology. Topology studies how the shape of a space behaves and how it can be continuously deformed. A space is called simply connected if any loop (closed curve) within it can be continuously shrunk to a single point. A space with this property is referred…