- #1
LagrangeEuler
- 717
- 20
If for some functional ##I##, ##\delta I=0## where ##\delta## is symbol for variation functional has extremum. For ##\delta^2 I>0## it is minimum, and for ##\delta^2 I<0## it is maximum. What if
##\delta I=\delta^2 I=0##. Then I must go with finding further variations. And if ##\delta^3I>0## is then that minimum? Or what?
##\delta I=\delta^2 I=0##. Then I must go with finding further variations. And if ##\delta^3I>0## is then that minimum? Or what?