The Circle Approach to Trigonometry

Autor/inn/en	Moore, Kevin c.; LaForest, Kevin R.
Titel	The Circle Approach to Trigonometry
Quelle	In: Mathematics Teacher, 107 (2014) 8, S.617-623 (8 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0025-5769
Schlagwörter	Trigonometry; Mathematics Instruction; Mathematical Concepts; Mathematical Logic; Logical Thinking; Measurement; Secondary School Mathematics; Graphs; Geometric Concepts; Problem Solving + Suchen Sie Ihr Suchwort? Trigonometrie; Mathematics lessons; Mathematikunterricht; Mathematical logics; Mathematische Logik; Messverfahren; Grafische Darstellung; Elementare Geometrie; Problemlösen
Abstract	How do students think about an angle measure of ninety degrees? How do they think about ratios and values on the unit circle? How might angle measure be used to connect right-triangle trigonometry and circular functions? And why might asking these questions be important when introducing trigonometric functions to students? When teaching trigonometric functions, most teachers would agree that students have difficulty using trigonometric functions to relate quantities in circle and right-triangle contexts. If students are to use trigonometric functions productively, they must understand angle measure, the unit circle, and right triangles in ways that let them see trigonometric functions as relations between two quantities. In addition, trigonometry instruction should adhere to the Common Core State Standards for Mathematics' emphasis on students' quantitative reasoning (CCSSI 2010). In this article, Kevin Moore and Kevin LaForest draw from recent research on student learning in trigonometry to illustrate a connected introduction of angle measure and the sine function that entails quantitative reasoning. To demonstrate these ideas in practice, they provide examples of precalculus students' solutions to various trigonometry problems. The ideas presented here also outline nuances involved in increasing student learning during a sequence of activities like that presented by Landers (2013). In particular, they draw attention to reasoning about varying quantities in the context of graphing and how issues of measurement help students understand the unit circle and ratios. (ERIC).
Anmerkungen	National Council of Teachers of Mathematics. 1906 Association Drive, Reston, VA 20191-1502. Tel: 800-235-7566; Tel: 703-620-3702; Fax: 703-476-2970; e-mail: orders@nctm.org; Web site: http://www.nctm.org/publications/
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2017/4/10