Electric and magnetic fields propagate as waves through a vacuum. Write equations that describe a plane electromagnetic wave propagating in the z direction and do the following: (use Maxwell equations)
a) E = E_0 * sin(kz - ωt)
b) B = B_0 * cos(kz - ωt)
c) E = E_0 * cos(kz + ωt)
d) B = B_0 * sin(kz + ωt)