Two loudspeakers are located 2.81 m apart on an outdoor stage. A listener is 16.8 rn from one and 18.5 m from the other. During the sound check, a signal generator drives the two speakers in phase with the same amplitude and frequency. The transmitted frequency is swept through the audible range (20 Hz to 20 kHz). (3) What is the lowest frequency fmin,1 that gives minimum signal (destructive interference} at the listener's location? By what number must fmin,1 be multiplied to get (b) the second lowest frequency fmin,2 that gives minimum signal and (c) the third lowest frequency fmingg that gives minimum signal? (d) What is the lowest frequency fmax,1 that gives maximum signal (constructive interference) at the listener's location? By what number must fmax,1 be multiplied to get (e) the second lowest frequency fmaxz that gives maximum signal and (f) the third lowest frequency fmax that gives maximum signal? (Take the speed of sound to be 343 m/s.) (3) Number I Units Hz V (b) Number Units Nounits v (c) Number Units Nounits V (e) Number Units v (f) Number Units v (d) Number l Units v