Question

plz show all steps and do both a and b

Exercise 13.7 (a) Show that Eq. (13.90) is the sum of Eqs. (13.85) and (13.87) E1 (x, z)=-2E jcos0;sin(B1zcos0) + 2 sin0,cos(Bjzcos0)]eisin [V/m] (13.90) V/m Ef(x, 2) = Ei(xcos0 - isin 0)eb(2sin6; +zcos@) (13.85) Er-Ncos0;- isin0)e~ib1(xsin®, -zcos0) E,(x, z [V/m] (13.87) Exercise 13.7 (a) Show that Eq. (13.90) is the sum of Eqs. (13.85) and (13.87), and Eq. (13.91) is the sum of Eqs. (13.86) and (13.88) (b) Calculate the time-averaged Poynting vector for the total fields and show that waves direction and waves in the z direction are standing waves. propagate in the positive