Fuente TeX:

\dfrac {df} {d\alpha} = \dfrac g l \dfrac {\{-2 \cos \alpha + \sin \alpha \}}{4/3 + \sin^2 \alpha} - \dfrac g l \dfrac { \{ 2(\sin\alpha_0 - \sin \alpha)+\cos \alpha_0 - \cos \alpha \} }{(4/3 + \sin^2 \alpha)^2} \times 2 \sin \alpha \cos \alpha