ERIC Number: EJ720444
Record Type: Journal
Publication Date: 2004
Reference Count: 3
The Prosthaphaeretic Slide Rule: A Mechanical Multiplication Device Based on Trigonometic Identities
Sher, David B.; Nataro, Dean C.
Mathematics and Computer Education, v38 n1 p37-43 Win 2004
The typical precalculus book contains the obscure trigonometric identities known as the product-to-sum formulas. They usually get short treatment (or none) in a precalculus course because they are so rarely used. This is unfortunate since they have an interesting history. Before the invention of logarithms they were used to perform multiplications and divisions by a process known as prosthaphaeresis. Since the slide rule is a computational device based on logarithms, the authors wondered if a similar device based on prosthaphaeresis could be constructed. It can. They call it the "prosthaphaeretic slide rule".
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Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Authoring Institution: N/A