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Hex
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Brouwer’s Fixed-Point Theorem
Here, I’ll discuss a famous fixed-point theorem from topology. Definition and Statement of the Theorem A fixed point is literally a point that moves to itself when moved by a continuous mapping. Formally, let \( X \) be a topological space, and \( f:X→X \) a continuous map. A point \( x \) that satisfies…
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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
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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…