1. The function of function( chainrule etuFf(x, y), z=gu, v) z z [-]=[-].[] O L 2. The total influence rule Let uf(x,y) au [△a]=[-」×[△x]+ ]×[Ay] OX 1. Inverse application of the function of function rule Opl Op2 z -x op3 x 3×O Dp2=Op1. The function of function(chain)rule Let u=f(x,y), z=g(u,v) [ ] [ ].[ ] x u u z x z     =   2. The total influence rule Let u=f(x,y) [ ] [ ] [ ] [ ] [ y] y u x x u u       +    = 1. Inverse application of the function of function rule: 3 2 1 z 1 1 Op3 2 Op Op Op z x Var x Op Op  = ⎯⎯ ⎯⎯ ⎯⎯