Interestingly, these radio transmitters oscillate out of phase with each other. (B) is one quarter cycle behind (A), (C) is one quarter cycle behind (B), and (D) is one quarter cycle behind (C). (a) Consider a point P on the +x-axis at x = +R, where R . Let I0 denote the intensity that would be received at point P if only one tower were operating. What is the intensity received at P when all four towers are operating?