Resumen

Understanding trigonometry relational system is a school mathematics demanding topic. The angle, the unit circle and the trigonometric functions are its foundational notions. Trigonometric contents meaning and their understanding involve these three concepts and their relationships. This research aims to deepen in the pre-service teachers’ understanding about the angle, the unit circle and the trigonometric function when converting notions between two trigonometric representation systems based on the unit circle and the trigonometric functions. The results indicate that pre-service mathematics teachers’ present a lack of connections between the goniometric and the analytical representation systems.