ual ▁problem ▁ ▁L agr ang ian , ▁a ▁functional ▁whose ▁ext re ma ▁are ▁to ▁be ▁determined ▁in ▁the ▁calculus ▁of ▁variations ▁ ▁L agr ang ian ▁sub man if old , ▁a ▁class ▁of ▁sub man if olds ▁in ▁sym ple ctic ▁geometry ▁ ▁L agr ang ian ▁system , ▁a ▁pair ▁consisting ▁of ▁a ▁smooth ▁fi ber ▁bundle ▁and ▁a ▁L agr ang ian ▁density ▁ ▁Physics ▁ ▁L agr ang ian ▁mechan ics , ▁a ▁reform ulation ▁of ▁classical ▁mechan ics ▁ ▁L agr ang ian ▁( field ▁theory ), ▁a ▁formal ism ▁in ▁classical ▁field ▁theory ▁ ▁L agr ang ian ▁point , ▁a ▁position ▁in ▁an ▁orb ital ▁configuration ▁of ▁two ▁large ▁bodies ▁ ▁L agr ang ian ▁coordinates , ▁a ▁way ▁of ▁describing ▁the ▁mot ions ▁of ▁particles ▁of ▁a ▁solid ▁or ▁fluid ▁in ▁continu um ▁mechan ics ▁ ▁L agr ang ian ▁coh er ent ▁structure , ▁distinguished ▁surfaces ▁of ▁traject ories ▁in ▁a ▁dynam ical ▁system ▁ ▁See ▁also ▁ ▁Joseph - Louis ▁Lag range ▁( 1 7 3 6 – 1 8 1 3 ), ▁Italian ▁math ematic ian ▁and ▁astronom er ▁ ▁Lag range ▁( disambiguation ) ▁ ▁List ▁of ▁things ▁named ▁after ▁Joseph - Louis ▁Lag range <0x0A> </s> ▁Bad am est an ▁( , ▁also ▁Roman ized ▁as ▁B ā d ā m est ā n ; ▁also ▁known ▁as ▁Bad am istan ) ▁is ▁a ▁village ▁in ▁Bon ab ▁R ural ▁District , ▁in ▁the ▁Central ▁District ▁of ▁Z