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regpoly-Abstract

Abstract Out of all prime-sided regular polygons, only 5 of them are constructible by CSE (compass and straightedge) construction, it is unknown whether more of them exist. 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 40 etc. has been known since Ancient Greek. 17, 34, 51, etc. was proven constructible by Gauss. Out of all 98 n-gons from n=3 to n=100, only 24 of them constructible by CSE (see Gauss-Wantzel Theorem). Although for most basic geometric construction like perpendicular line, parallel line, midpoint construction, etc. CSE is feasible, it is not fundamental and has its own limits. Solutions of polynomial  $$x^n-1=0$$ forms vertices of a regular \(n\)-gon in complex plane, inscribed in unit circle with one vertice being \(0+0i\) which is a trivial solution for polynomial above but notice that it factors into $$x^n-1=(x-1)(x^{n-1}+x^{n-2}+\cdots+x^2+x^1+1)$$

Geometry

p1 p2 p3 Unit Vector (grade 1) $$e_1\quad,e_2\quad,e_3\quad,e_4\quad\dots$$ depending on the dimension used Unit Bivector (grade 2) 2D : $$\quad e_1e_2$$ 3D : $$\quad e_1e_2,\quad e_1e_3,\quad e_2e_3$$ 4D : $$\quad e_1e_2,\quad e_1e_3,\quad e_1e_4,\quad e_2e_3,\quad e_2e_4,\quad e_3e_4$$ etc. depending on dimension used Unit Trivector (grade 3) 3D : $$\quad e_1e_2e_3$$ 4D : $$\quad e_1e_2e_3,\quad e_1e_2e_4,\quad e_1e_3e_4,\quad e_2e_3e_4$$ etc. depending on dimension used 2D Setup : $$\overset{\text{scalar}}{{1}}\quad\quad\overset{\text{vector}}{\overbrace{e_1\quad\quad e_2}}\quad\quad \overset{\text{bivector}}{\overbrace{e_1e_2}}$$ $$a=a_1e_1 + a_2e_2$$ $$b=b_1e_1 + b_2e_2$$ Addition $$\begin{array}{ll}a+b&=(a_1+b_1)e_1+(a_2+b_2)e_2\end{array}$$ Multiplication (Product) Warning : not commutative $$\begin{array}{ll}ab&=(a_1b_1 + a_2b_2) + (a_1b_2 - a_2b_1)e_1e_2\end{array}$$ $$\begin{array}{ll}ab &=(a_1e_1 + a_2e_2)(b_1e_1 + b_2e_2) \\ \\ &=a_1e_1(b_1e_1 + b_2e_2) + a_...

Forsnel-01

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 magnifikan posting

Skoren

 Hi h Clifford Algebra $\mathrm{Cl}(0,2)$ $$\begin{array}{ll} \text{scalar}\quad&\text{grade 0}\\ \text{vector}\quad&\text{grade 1}\\ \end{array} $$ m l t Majora Maksen Mgnest Maksenag Hi h Clifford Algebra $\mathrm{Cl}(0,2)$ $$\begin{array}{ll} \text{scalar}\quad&\text{grade 0}\\ \text{vector}\quad&\text{grade 1}\\ \end{array} $$ m l t

Neusis IV

  Tridecagon Neusis let \(f(x)\) be \(13^{th}\) roots of unity  $$f^x=f(x)$$ for all \(x\in\mathbb{Z}\), \(f(x)\) forms a regular heptagon on unit circle in complex plane and satisfies $$f(x)^{13}=1$$ which factors into $$\Big(f(x) - 1\Big)\Big(f(x)^{12} + f(x)^{11} + \cdots + f(x)^2 + f(x)^1 + 1\Big)=0$$ which we can obtain from (where \(f(x)\neq1\)  $$f(12x) + f(11x) + \cdots + f(x) = -1$$ let $$p(x)=f(x) + f(3x) + f(9x) $$ we have  $$\begin{array}{lllll}p(x)&=p(3x)&=p(9x)\\ \\p(2x)&=p(6x)&=p(5x)\\ \\p(4x)&=p(12x)&=p(10x)\\ \\p(8x)&=p(11x)&=p(7x)\\ \\p(13x)&=3\end{array}$$ 9

Neusis III

Proof | Hendecagon construction by Neusis for any complex number \(z\) : $$z + z^*\in\mathbb{R}$$ $$z z^*\in\mathbb{R}^{+}$$ $$\dfrac{\sqrt{\overset{\phantom{0}}{zz^*}}}{z^*}\in\mathbb{S}^{1}$$ $$z - z^*\in\Big\{ix\mid x\in\mathbb{R}\Big\}$$ let \(f(x)\) be \(11^{th}\) roots of unity  $$f^x=f(x)$$ for all \(x\in\mathbb{Z}\), \(f(x)\) forms a regular heptagon on unit circle in complex plane and satisfies $$f(x)^{11}=1$$ which factors into $$\Big(f(x) - 1\Big)\Big(f(x)^{10} + f(x)^9 + \cdots + f(x)^2 + f(x)^1 + 1\Big)=0$$ which we can obtain from (where \(f(x)\neq1\)  $$f(10x) + f(9x) + f(8x) + f(7x) + f(6x) + f(5x) + f(4x) + f(3x) + f(2x) + f(x) = -1$$ let $$p(x)=f(x) + f(4x) + f(5x) + f(9x)+f(3x)$$ we have  $$\begin{array}{lllll}p(x)&=p(4x)&=p(5x)&=p(9x)&=p(3x)\\ \\p(2x)&=p(8x)&=p(10x)&=p(7x)&=p(6x)\\ \\p(11x)&=5\end{array}$$ $$\Big(p(x)\Big)^*=p(2x)$$ $$p(x) + p(2x) = -1$$ which shows that \(p(x),p(2x)\) lies on line \(z+z^*=-1\) ...

Neusis II

  Proof | Heptagon Construction by Neusis let \(f(x)\) be \(7^{th}\) roots of unity  $$f^x=f(x)$$ for all \(x\in\mathbb{Z}\), \(f(x)\) forms a regular heptagon on unit circle in complex plane and satisfies $$f(x)^7=1$$ which factors into $$\Big(f(x) - 1\Big)\Big(f(x)^6 + f(x)^5 + f(x)^4 + f(x)^3 + f(x)^2 + f(x)^1 + 1\Big)=0$$ which we can obtain from (where \(f(x)\neq1\)) $$f(6x) + f(5x) + f(4x) + f(3x) + f(2x) + f(x) = -1$$ let $$p(x)=f(x) + f(2x) + f(4x)$$ we can find that $$\begin{array}{llll}p(x)&=p(2x)&=p(4x)\\ \\p(3x)&=p(6x)&=p(5x)\\ \\p(7x)&=3\end{array}$$ $$\begin{array}{ll}\Big(p(x)\Big)^*&=f(x)^*+f(2x)^*+f(4x)^*\\ \\&=f(6x)+f(5x)+f(3x)\\ \\&=p(3x)\end{array}$$ $$p(x) + p(3x) = -1$$ which shows that \(p(x), p(3x)\) lies on line \(z+z^*=-1\), and $$\begin{array}{llllllll}p(x)\cdot p(3x) &=& &f(3x) &f(6x) &(5x)&=p(x)+p(3x)+3&=2\\ \\ &&f(x)&f(4x)&1&f(6x)\\ \\ &&f(2x)&f(5x)&f(x...