Funciones Trigonométricas#

Fig. 20 Rogawski Calculus, Second Edition Copyright © 2012 W. H. Freeman and Company#
\[
\sin\theta =\frac{b}{c}=\frac{\text{opuesto}}{\text{hipotenusa}},\qquad
\cos\theta =\frac{a}{c}=\frac{\text{adyacente}}{\text{hipotenusa}}
\]
Círculo unidad#

Fig. 21 Rogawski Calculus, Second Edition Copyright © 2012 W. H. Freeman and Company#
Propiedades
\[
\sin(-\theta)=-\sin\theta,\qquad \cos(-\theta)=\cos(\theta)
\]