The finite element method obtains the correct solution for any finite element model by. minimizing the energy functional. The minimum of the functional is found by setting the. derivative of the functional with respect to the unknown grid point potential for zero.
Traditionally, 12 days. It goes from Christmas Day, Dec 25, through January 6th, the day of Epiphany. However Its different for different people. For Secular people the secular Christmas lasts usually one or 2 days. However for religious people such as most Christians Christmas actually lasts for 12 days.
Epiphany is the climax of the Advent/Christmas Season and the Twelve Days of Christmas, which are usually counted from the evening of December 25th until the morning of January 6th, which is the Twelfth Day.