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Proof Without Words: Double Sum for Sine and Cosine

by Hasan Unal (Yildiz Technical University, Turkey)

This article originally appeared in:
College Mathematics Journal
November, 2010

Subject classification(s): Geometry and Topology | Geometric Proof
Applicable Course(s): 2.2 Trigonometry

The author proves visually the double angle formulas for sine and cosine.

A pdf copy of the article can be viewed by clicking below. Since the copy is a faithful reproduction of the actual journal pages, the article may not begin at the top of the first page.

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Capsule Course Topic(s):
Development Math | Formulas
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