Sharp inequalities for sine and cosine on complex circles and applications. International Journal of Open Problems in Computer Science and Mathematics, [S. l.], v. 19, n. 3, p. 37–51, 2026. DOI: 10.15849/ijopcm.v19i3.68. Disponível em: https://ijopcm.zuj.edu.jo/index.php/IJOPCM/article/view/68. Acesso em: 16 oct. 2026.