Question: Two loudspeakers on a concert stage are vibrating in phase. A listener is 47.3 m from the left speaker and 32.1 m from the right one. The listener can respond to all frequencies from 20 to 20 000 Hz, and the speed of sound is 343 m/s.
Part A: What is the lowest frequency that can be heard loudly due to constructive interference?
I need expert help to find the lowest frequency that can be heard loudly.