Answer:
A) max = Eo = 375 V/m, B)  B = 125 10⁻⁸ T
, C) f = 9.50 101⁴ Hz, D) λ = 3.158 10⁻⁷ m, E)  T = 1.05 10⁻¹⁵ s
, F) invisible for humans   G)  v = c = 3 10⁸ m/s
Explanation:
The expression given for the electric field is
        E = 375 cos (1.99 107x + 5.97 105t)
The general formula for the electric field of a transverse traveler is
      E = Eo cos (kx-wt)
Where k is the wave number and w the angular velocity
A) The amplitudes as electric is
      Emax = Eo = 375 V / m
B) the electric and magnetic field are related
      E / B = c
      B = E / c
      B = 375/3 108
      B = 125 10⁻⁸ T
C) angular velocity and frequency is related
     .w = 2π f
      f = w / 2π
      f = 5.97 10¹⁵ / 2π
      f = 9.50 101⁴ Hz
D) the speed of light has the formula
       c = λ f
       λ = c / f
       λ = 3 10⁸ / 9.50 10¹⁴
       λ = 3.158 10⁻⁷ m
E) The period
      T = 1 / f
      T = 1 / 9.5 10¹⁴
      T = 1.05 10⁻¹⁵ s
F) let's reduce the wavelength nm
    λ = 3.158 10⁻⁷ m (10⁹nm / 1m)
    λ = 3.158 10²nm = 315.3 nm
The visible radiation range is between 400nm and 700nm. This radiation is ultraviolet and is invisible humans
G) All electromagnetic radiation has a speed at the speed of light (c)
       v = c = 3 10⁸ m/s