• Honam Mathematical Journal
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• v.30 no.1
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• pp.185-195
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• 2008

We consider a system of trigonometric functional equations in the spaces of generalized functions such as Schwartz distributions and Gelfand generalized functions. As a consequence we find locally integrable solutions of the n-dimensional trigonometric functional equation.

• Journal of the Chungcheong Mathematical Society
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• v.35 no.1
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• pp.33-37
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• 2022

In this short note, we prove an open problem for the interval (-∞, ∞), related to a reverse trigonometric Masjed-Jamei inequality presented in [2] and establish a new inequality of a similar kind.

• Korean Journal of Mathematics
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• v.19 no.4
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• pp.465-480
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• 2011

B. C. Berndt established many identities about infinite series. In this paper, continuing his work, we find new identities about infinite series containing hyperbolic functions and trigonometric functions.

• Communications of Mathematical Education
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• v.22 no.3
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• pp.289-310
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• 2008

The purpose of study is to propose the possibilities of finding trigonometric function values using trigonometric function graphs instead of the unit circle method. And it is to discuss how to enhance relating trigonometric function value finding to graphs construction, and students conceptual understanding of the properties of trigonometric functions. The conclusions of this study are the effectiveness of function value finding using trigonometric function graphs, the use of a precise term of function value finding given general angles, consideration of a link between function value finding and graphs, and the possibility of teaching trigonometric function graphs in advance of function value finding.

• The Mathematical Education
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• v.49 no.3
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• pp.353-373
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• 2010

This research was to help slow learners to be motivated and to make their outcome productive, using GSP based on the mathematization theory for learning mathematics, as a way of encouraging the learner-centered approach. With 2 of the second graders in a high school, who had not yet understood trigonometric functions in their first grade period, 7 units of lesson plans were designed for the research. The results showed that first, understanding real life contexts and analyzing properties by observation, and experiment using GSP, to build the concept of trigonometric functions could be a foothold on which learner's organization and outcome from a horizontal mathematization led to vertical mathematization. Despite the delay during the level-up-stage for a while, the learners could attain the vertical mathematization stage and moreover the applicative mathematization through effective use of GSP and the interaction between the learners or a teacher and the learners. Second, using GSP was a vertical tool of connecting horizontal mathematization with vertical mathematization in forming the concept of trigonometric functions and its meaning could be understood by their verbalizing and presenting the outcomes through their active performance. Using GSP is helpful for slow learners to overcome learning difficulties, based on the instructional materials designed by Realistic Mathematics Education.

• Journal of applied mathematics & informatics
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• v.39 no.1_2
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• pp.83-91
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• 2021

In this paper, we introduce the concepts of q-cosine tangent polynomials and q-sine tangent polynomials. From these polynomials, we find some identities and properties by using q-numbers and q-trigonometric functions.

• School Mathematics
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• v.11 no.1
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• pp.111-129
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• 2009

This paper is about didactical transposition, which is to transpose academic knowledge into practical knowledge intended to teach. The research questions are addressed as follows. 1. Are the 13 mathematics textbooks of the 10-Na level indisputable regarding with the didactical transposition, in terms that the order of arrangement and the way of explaining the knowledge of trigonometric functions being analyzed and that its logical construction and students' understandings are considered? 2. Can some transpositions for easier use of didactical manipulative, for more practical and for more principle based be proposed? To answer these questions, this research examined previous studies of mathematics education, specifically the organization of the textbook and the trigonometric functions, and also compared orders of arranging and ways of explaining trigonometric functions from the perspective of didactical transposition of 13 versions of the 10-Na level reorganized under the 7th curriculum. The paper investigated what lacks in the present textbook and sought a teaching guideline of trigonometric functions(especially about sector and graph, period, characters of trigonometric function, and sine rule).

• East Asian mathematical journal
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• v.26 no.4
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• pp.487-507
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• 2010

We study mathematization of natural thinking and some materials developed in geometric construction of regular n-polygons. This mathematization provides a nice model for illustrating interesting approaches to trigonometric functions and trigonometric ratios as well as their inter-connections. Thereby, results of this paper will provide the procedure of the development for these concepts in natural way, which will be helpful for understanding background knowledges.

• Journal of applied mathematics & informatics
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• v.19 no.1_2
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• pp.513-520
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• 2005

We calculate the normal fuzzy probability for trigonometric fuzzy numbers defined by trigonometric functions. And we study the normal probability for some operations of two trigonometric fuzzy numbers. Furthermore, we calculate the normal fuzzy probability for some fuzzy numbers generated by operations.

• Journal of Advanced Navigation Technology
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• v.27 no.3
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• pp.274-280
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• 2023

The Fix-to-Fix Navigation is the technique for aircraft pilots to find out estimated Heading when crossing from present fix to other fix to want to go in the air. Because this is based on the Rule of Thumb method from one's experience, it could not find out exact estimated Heading. Furthermore if the pilot nears going fix, Bearing Pointer and Course Indicator of HSI are too close to use this technique, that makes the pilot lost in the air. In this paper, We take Limits of Trigonometric Functions into the Fix-to-Fix Navigation to overcome these disadvantages. This study introduces two solutions using Limits of Trigonometric Functions when doing Fix-to-Fix Navigation and analyzes the error of this solutions.