Trigonometry, a branch of mathematics that deals with the relationships between the sides and angles of triangles, has been a cornerstone of mathematical and scientific inquiry for centuries. At the heart of trigonometry lies a set of fundamental functions, namely sine, cosine, and tangent, which are intricately connected and form the basis of trigonometric identities. This article will delve into the relations between these trigonometric functions, exploring their interconnectedness and the various ways in which they can be manipulated and utilized.

trigonometry, characteristics, studies, main concepts, relations, trigonometric functions

Joseph, George G., The Crest of the Peacock: Non-European Roots of Mathematics, 2nd ed. Penguin Books, London. (2000). ISBN 0-691-00659-8.

Kantabutra, Vitit, "On hardware for computing exponential and trigonometric functions," IEEE Trans. Computers 45 (3), 328–339 (1996).

Maor, Eli, Trigonometric Delights, Princeton Univ. Press. (1998). Reprint edition (2002): ISBN 0-691-09541-8.

Needham, Tristan, "Preface"" to Visual Complex Analysis. Oxford University Press, (1999). ISBN 0-19-853446-9.

Nielsen, Kaj L. (1966), Logarithmic and Trigonometric Tables to Five Places (2nd ed.), New York: Barnes & Noble, LCCN 61-9103

O'Connor, J. J., and E. F. Robertson, "Trigonometric functions", MacTutor History of Mathematics archive. (1996).

O'Connor, J. J., and E. F. Robertson, "Madhava of Sangamagramma", MacTutor History of Mathematics archive. (2000).

Pearce, Ian G., "Madhava of Sangamagramma" Archived 2006-05-05 at the Wayback Machine, MacTutor History of Mathematics archive. (2002).