V×H=E OE (3) at i j k V×H= OHr_OHyE ax a dZ y aZ y H HH OH OH OH OH az ax ax dy aE aE 8k ot at at 等式两边对应的分量应相等。× Δ = t E   H e (3) × Δ H = x  i y  j z  k Hx Hy Hz x  y H  y Hx + k z  x H  x Hz + j y  z H  z Hy = i i + j k t Ez e t Ex e t Ey = e + 等式两边对应的分量应相等