Protection Bracelet 144 - Light framed by dark

A creative spark led me to design my own take on a chosen bracelet.

6mm natural stone. Repeated for symmetry and structural balance.

#copenhagen #bracelet #SymmetryMatters #PatternLanguage #BuiltWithIntention #StructuredEnergy #LightWithin #FieldWork #QuietSignals #SacredGeometry #MakerMindset #BetweenLines #ThoseWhoKnow

When a calculus student ends up solving this integral using partial fraction decomposition (PFD) or integration by parts (IBP), what they have actually done is successfully applied a classical algorithm. It’s like solving the Rubik’s cube by following an algorithm you found on the Internet: the heavy lifting of inventing PFD and IBP was done centuries ago by Bernoulli, Leibniz, and Gregory.

That said, the USM is, as far as I know, the only published general scheme that, for this kind of radical–rational integrals, systematically reduces the integrand to polynomial-type functions (Laurent polynomials, to be more precise). There’s no need to set up complicated PFDs or wrestle with sec³, which can be tricky with IBP. That’s what I call solving a problem, if you’ll allow me a bit of self-promotion.

You can find a first draft (I’ll soon upload a second version with benchmarks and some improvements) of the USM method on arXiv: https://arxiv.org/abs/2505.03754

#calculus #math #symmetrymatters #halfangleapproach #euler #integration

Hey, I just generalized the 𝐥𝐚𝐰 𝐨𝐟 𝐜𝐨𝐭𝐚𝐧𝐠𝐞𝐧𝐭𝐬! Take a look at it on my blog: https://geometriadominicana.blogspot.com/2025/08/generalization-of-law-of-cotangents.html

#math #geometry #trigonometry #halfangleapproach #symmetrymatters

USM really does slash the rote burden, chiefly because one handful of exponential/hyperbolic identities replaces a patchwork of separate trig, inverse-trig, radical and Euler recipes.

Article (draft): https://arxiv.org/abs/2505.03754

#math #calculus #integral #new #euler #arxiv #halfangleapproach #symmetrymatters

A Unified Substitution Method for Integration

We present a branch-consistent framework for integrals involving quadratic radicals by expressing exponentials of principal inverse trigonometric functions in algebraic form. Two identities for $e^{\pm i\cos^{-1}(y)}$ and $e^{\pm i\sec^{-1}(y)}$ on principal branches yield five explicit substitution templates that map common radicals and half-angle composites to rational functions of a single parameter. The resulting differentials are independent of the sign choice once the branches are fixed, reducing domain bookkeeping across circular and hyperbolic regimes. We recover Euler's first and second substitutions from these transforms up to trivial reparametrizations and provide worked examples; in particular, the classical Weierstrass substitution is obtained as a direct corollary of Transform 5. A binomial-difference identity streamlines back-substitution terms such as $t^n - t^{-n}$. A CAS benchmark of 100 integrals indicates improved predictability and reduced expression swell relative to general-purpose integration routines.

arXiv.org

The first and most complete unification of classical integration techniques ever! Say hello to USM.

Draft article: https://drive.google.com/file/d/12DayP6cD1VwDIZCL-nMlcaNH2XUwHfAy/view?usp=drivesdk

#math #calculus #halfangleapproach #symmetrymatters

A_Unified_Substitution_Method_for_Integration__DRAFT_.pdf

Google Docs

The USM, the Dominican method 🇩🇴, has relegated Euler substitutions to mere historical relics. Modern integration has a new name.

Method draft: https://drive.google.com/file/d/12DayP6cD1VwDIZCL-nMlcaNH2XUwHfAy/view?usp=drivesdk
#math #calculus #integrals #method #euler #halfangleapproach #symmetrymatters

A_Unified_Substitution_Method_for_Integration__DRAFT_.pdf

Google Docs

The USM is superior to traditional methods!

Using the USM’s IV transformation formula, from the summary at the link below, you convert integrals of this type into polynomial-type integrals. The traditional method reduces it to the integral of csc³, which would require complicated reduction formulas or integration by parts. The third Euler substitution reduces it to the integral of √(t² + a²), which also requires memorizing a standard formula or integrating it from scratch. None of this is as simple as integrating a three-term polynomial-type function, which is taught in the first few weeks of any integral calculus course.

Check out the technique here: http://geometriadominicana.blogspot.com/2024/03/integration-using-some-euler-like.html
#math #calculus #integration #USM #newmethod #halfangleapproach #symmetrymatters

A new integration technique via Euler-like identities

"Complexification formulas are great and it seems like this simplifies the right away." - Ninad Munshi Introduction While investigating a wa...

I gave this integral as an answer at MathSE.

\[\int_{0}^{1}\left(\frac{5}{2} \left((x - \sqrt{x^2 - 1})^{2i} + x^4\right)-1\right)\,dx=e^\pi.\]

The integral yields \(e^{\pi}\). I don't know why the LaTeX isn't displaying properly.

Link: https://math.stackexchange.com/questions/122693/is-there-a-definite-integral-that-yields-e-pi-or-e-pi-in-a-non-trivial/4861138?fbclid=IwAR3CPXtBoNDY3yc5a1HDAgfWN7QFAO2Ph91uvH7MUgSxSRjsq-t8TWYHWdY#4861138

#math #integral #eulernumber #halfangleapproach #symmetrymatters #calculus

Is there a definite integral that yields $e^\pi$ or $e^{-\pi}$ in a non trivial way?

The title says it all. No trivial answers like $\int_0^\pi e^tdt$ please. The idea is rather, if there are integrals like $$\int\limits_0^\infty \frac{t^{2n}}{\cosh t}dt=(-1)^{n}\left(\frac{\pi}2\r...

Mathematics Stack Exchange
An 'impossible' integral to solve (Mathematica fails):
\[\int_{2}^{3} \frac{{1 - \tan\frac{{\sec^{-1}x}}{2}}}{{1 + \tan\frac{{\sec^{-1}x}}{2}}}\sqrt{\tan\frac{\csc^{-1}x}{2}} \,dx\]
Unless you know my new technique:
https://mathoverflow.net/questions/463459/identities-that-simplify-tedious-integrals?noredirect=1#comment1203657_463459
#math #impossibleintegral #calculus #halfangleapproach #symmetrymatters
Identities that simplify tedious integrals

The following identities have been suggested based on formulas in a previous question of mine. If complex $\theta_1=\cos^{-1}(p)$ and $\theta_2=\sec^{-1}(p)$, where $p\geq-1$ and $p\neq0$, then the

MathOverflow

In my latest blog post, I have derived what appears to be a new formula for solving quadratic equations. Were you aware of it?

Link: https://geometriadominicana.blogspot.com/2024/01/trigonometric-formula-for-solving.html

#math #halfangleapproach #symmetrymatters

Trigonometric formula for solving quadratic equations

In this note, we provide an alternative trigonometric formula for solving quadratic equations where $a$, $b$, and $c$ are real numbers. If ...