H/dC1=0,i=1,2,3, 解出参数C ■代回得近似值 E=H(C1,C2)◼ 解出参数Ci ’ ◼ 代回得近似值 H / C = 0,i = 1,2,3,....   i ( ' , ' ,..) E = H C 1 C 2