how to solve

Problem 2.4 (Textbook Problem P2.16) Let the tangential E-field and tangential H-field on a closed surface S be related by an impedance matrix Z(r) such that AXE = Z(r) . (1 x H) , where fi is the outward normal to the surface S bounding the region of interest V and Z(r) = $2221$1 $272252 $1 and $2 are unit vectors tangential to the surface S such that $1, $2, and fi form right- handed orthogonal coordinates and z are real constants. Denote E = EIS, + E2$2 + Ens, and H = HIS1 + H2$2 + HmSn- (a) Show that El = -221 H2 + Z22 HI and E2 = ZUIH2 -212HI . (b) Determine the condition for elements z such that the uniqueness theorem holds