4.8 Find the phasors for the following field quantities: (a) E,(z, t) = E, cos (wt - Bz+ b) (V/m) (b) E,(z. t) = 100e ³ cos (wt - 5z+#/4) (V/m)

(c) H₂(z, t) = H, cos (wt + Bz) (A/m) (d) H,(z, t) = 120me cos (wt + ßz + ₂) (A/m)