PDF-Symbol: pdfreaders.org.

Mathematical proofs are used to prove the cor­rect­ness of formulas and assumed facts. Sev­er­al basic procedures and ways of veri­fy­ing mathematical correctness are in use, all of which follow a fixed scheme.

For the proof of the irrationality of the square root of 2 dif­fer­ent proofs exist. This article explains the indirect proof vari­ant in detail and introduces one of the possible short spell­ings in mathematical notation. Exercises with solutions con­soli­date what has been learned. 13 pages::

      A4  •  A4 duplex  •  US-Letter  •  US-Letter duplex

Computer algebra systems pro­vide valuable services in check­ing calculated solutions. How­ever, many programs have high resource re­quire­ments. The free, Python-based computer algebra sys­tem Sympy (WP article) runs on both new and old sys­tems.

Learn more about the possibilities of modernizing an old com­put­er with specialized lightweight free distributions: “Intro­duc­tion to Free Software and Operating Systems”.

Scientific Publishing and Illustrating


An overview article introducing widely used free typesetting systems and basic docu­ment types, with extensive link lists: „Free Type­set­ting Software for the Professional Doc­ument Preparation“, with a mini-intro­duc­tion to basic technical (design) prin­ci­ples, including style sheets and style files.

Free software proves to be extremely flexible in importing and exporting mathematical typesetting elements and other file formats, word processors offer their own formula edi­tors as well as the possibility to import math formulas in the stand­ard format, in TeX (article sections): “Classical Type­set­ting in Highest Quality for Writers and Scientists: TeX, LaTeX, LyX” • “Free Text Editors and Recommended Read­ing on LaTeX, KOMA-Script & Co.”.


Mini Articles

        Originalbildquelle: http://everaldo.com/crystal/?action=downloads,
        Lizenz: http://everaldo.com/crystal/?action=license

School mathematics: Detailed so­lu­tions to the first 27 text problems of “A first book in Al­­ge­­bra”, author Wallace C. Boyden, added, a textbook for be­gin­ners in algebra: Text problems with solutions, 10 pages (PDF, A4 format).

September 17, 2021

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