We know that the standard equation of electromagnetic wave is given by:
Ey = E0cos(wt−kx)
The equation that is given is: Ey=2.5N/C cos[(2π × 106rad/s)t−(π × 10−2rad/mx)]
Now we have to compare the given equation with the standard equation.
On the comparison, we get that:
⇒ w = 2π×106
⇒ λf = 106Hz
It is also known to us that: 2πλ=k=π×10−2m−1
⇒ f = λ=200m
Hence we can say that the wave is moving along the positive x direction with a frequency of 106Hz and a wavelength of 200 m.