Rg(x,y,z) ˘hgx,gy,gzi˘hy¯2z,x¯2z,2y¯2xi Thus, we have the following four equations yz ˘ ‚(y¯2z), (1) zx ˘ ‚(x¯2z), (2) xy ˘ ‚(2y¯2x), (3) xy ¯ 2yz¯2zx¡12 ˘0 (4) There are four unknowns and four equations Hence we should be able to solve these Multiplying x to the both sides of (1) and y to those of (2) lead to xyz
