力法正则方程: 811X1+812X2+…+1nn+△1p=0 21X1+22X2+…+δ2nn+△2P=0 Sxi+ 6n,X2+…+ 2 +△ np 0力法正则方程：          11 1 12 2 1 1 21 1 22 2 2 2 1 1 2 2 0 0 0 X X X X X X X X X n n P n n P n n nn n nP + + + + = + + + + = + + + + =                