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View Full Version : Help with derivatives of tensors..


eljose79
Jan22-04, 01:27 PM
I have a problem when doing derivatives of some functions for example let be the lagrangian

L=gab(dxa/dt)(dxb/dt) my problem is to obtain the euler-lagrange equations in fact we would do

dL/dxa=(d/dt)(dl/d(dxa/dt) to get the geodesics but how would you do it..i have tried lots of times but i can not get the results of books...where is the trick?..