The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
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The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
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Persian mathematician and astronomer who wrote a commentary on Euclid's Elements and made early use of the trigonometric tangent function. Little is known of al-Nayrizi's life, but his name suggests that he came from the town of Nayriz in what is now central Iran and he probably served the Abbasid caliphs in Baghdad. In addition to his writings on Euclid and Ptolemy's Almagest and Tetrabiblos, al-Nayrizi discussed the problem of calculating the exact direction of Mecca, an important part of the Muslim daily prayer ritual. In so doing, he used the tangent function, though he was not the first to develop that concept.