7.26 The magnetic field of a plane wave propagating in anonmagnetic medium is given by \mathbf{H}=\hat{\mathbf{y}} 60 e^{-10 z} \cos \left(2 \pi \times 10^{8} t-12 z\right) \quad(\mathrm{mA} / \mathrm{m}) Obtain

the corresponding expression for E.