Al-Samaw’al’s Curious Approach to Trigonometry

• Autores: Glen Van Brummelen, Taro Mimura, Yousuf Kerai
• Localización: Suhayl: journal for the history or the exact and natural sciences in Islamic Civilisation, ISSN 1576-9372, Nº. 11, 2012, págs. 9-31
• Idioma: inglés
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• Resumen

  • Al-Samaw’al’s work Exposure of the Errors of the Astronomerscontains a single numerical table, a highly unusual table of sines. In order to avoid the problem of approximating sin(1 degree), al-Samaw’al redefines the number of degrees in a circle from 360 to 480. In theaccompanying chapter, al-Samaw’al criticizes his predecessors for deviating from geometrical preci-sion and explains how his table is to be calculated. However, our analysis demonstrates that al-Samaw’al did not follow his own instructions, simply interpolating his entries from a traditional sine table.