On page 13 in Landau-Lifgarbagez Mechanics, the total time time derivative of the Lagrangian of a closed system is given to be,(adsbygoogle = window.adsbygoogle || []).push({});

[tex]\frac{d L}{d t} = \sum_i \frac{\partial L}{\partial q_i} \dot{q_i} + \sum_i \frac{\partial L}{\partial \dot{q_i}} \ddot{q_i}[/tex]

Why does this stop here? I mean, why is the term [itex]\sum_i \frac{\partial L}{\partial \ddot{q_i}} \dddot{q_i}[/itex] not included?

An image of page 13 has been attached.

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# Landau Lifshitz - Total time derivative of the Lagrangian

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