Question: Two radio antennas are 120 m apart on a north-south line. The two antennas radiate in phase at a frequency of 5.6 MHz. All radio measurements are made far from the antennas. The smallest angle, reckoned north of east from the antennas,
Part A: At which destructive interference of the two radio waves occurs?
Please provide clear step by step solution with notes on concepts and equations being used.