• School Mathematics
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• v.12 no.2
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• pp.239-257
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• 2010

In school mathematics the derivative concept is intuitively taught with the tangents and the concept of instantaneous velocity. In this paper, I investigated the long historical developments of the derivative concepts and analysed the relationships between the definition of derivative and the related elements. Finally I proposed some educational implications based on the analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.108-117
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• 2009

Leissa claimed in his article that the Rayleigh method is not the same as the Ritz method for determining natural frequencies and its corresponding mode shapes and contended that Rayleigh's name should not be attached to the method. The present article examines the methods in viewpoint of admissible functions and its minimization process, and of the historical developments. It concludes that Leissa's assertion is relevant, although Rayleigh did apply a conceptual theory systematized from the Lagrange method, and given 38 years earlier than Ritz's 'masterly exposition of theory'.