A plane wave with the electric field vector given below is propagating in a lossless medium with $=9,=1.$

$($;$)=3$ cos$(2107$

$+)+4$ cos$(2107$

$+)$ V$/$m

a$)$ Explain what the polarization of the wave is$.(10$p$)$

b$)$ Determine the average power density vector carried by finding the Poynting vector.

Determine the total average power passing through a square region of side $2$ m located on the xy plane. $(20$p$)$