Definition of trigonometric functions on the entire real line was made possible by Euler's research not only permissible negative angles, but the angles of over 360 °.
Definition of imisebenzi Trigonometric emgqeni yangempela lwenziwe Sibonga kungenzeka ukuba ucwaninge Euler hhayi kuphela engeli kuvunyelwe negative, kodwa engele Bole 360 °.