His lasting achievement is found in his book Geometria rotundi (1583), where he introduced the trigonometric functions tangent and secant.
... - Ayrton Senna, (Brazil) 1988 - Alain Prost, (France) 1989 - Ayrton Senna, (Brazil) 1990 - Ayrton Senna, (Brazil) 1991 - Ayrton Senna, (Brazil) 1992 - Ayrton Senna, ...