The electric field of a wave propagating in the x-y plane, with wave vector \(\vec k\) making an angle of 60° with the x-axis is
1
\(\vec E = {E_0}\cos \left( {\omega t - \frac{{\sqrt 3 }}{2}kx + ky} \right)\)
2
\(\vec E = {E_0}\cos \left( {\omega t - \frac{{\sqrt 3 }}{2}kx -ky} \right)\)
3
\(\vec E = {E_0}\cos \left( {\omega t - \frac{1}2kx - \frac{{\sqrt 3 }}{2}ky} \right)\)
4
none