If the question had mentioned ##\overrightarrow{E}## instead of ##E_\bot##, then we could have used ##\overrightarrow{B}=\dfrac{1}{v}\widehat{k}\times \overrightarrow{E}## to get the direction of the magnetic field. But the question had only mentioned ##E_\bot##. To my understanding, knowing...
I wish I could edit my question again. The actual question reads, “Consider the interference of two coherent electromagnetic waves...” Thank you for your reply.
My Try:
The resultant field is given by
$$\begin{aligned}\overrightarrow{E}=\overrightarrow{E}_{1}+\overrightarrow{E}_{2}=\widehat{i} E_{0}\cos \omega t+\widehat{j}E_{0}\cos \left( \omega t+\phi \right) \\
\Rightarrow E^{2}=E_{0}^{2}\cos ^{2}\omega t+E_{0}^{2}\cos ^{2}\left( \omega t+\phi...