the question asks to find the ratio between E0 and B0 and the ratio between w and k

?

E and B are on the x-y plane

they are given as verctors without any components dividing

no x direction part,y direction part,z direction part

so when when i use the maxwell equations

i cant do the cross product of B or E

because i dont know what to put in the tererminant whch is calculating the cross product

i tried to make some components by my self

but i get so many variables