In Fig. , two speakers separated by distance d_1 = 2.00 m are in phase. Assume the amplitudes of the sound waves from the speakers are approximately the same at the listener's ear at distance d_2 = 4.00 m directly in front of one speaker. Consider the full audible range for normal hearing, 20 Hz to 20 kHz. (a) What is the lowest frequency f_("min".1) that gives minimum signal (destructive interference) at the listener's ear? By what number mustf_("min".1) be multiplied to get (b) the second lowest frequency f_("min".2)that gives signal and (c) the third lowest frequency f_("min".3)that givesr minimum signal? (d) What is the lowest frequency f_(max.1) that gives maximum signal (constructive interference) at the listener's ear? By what number must f_(max.1)be multiplied to get (e ) the second lowest frequency f_(max.2)that gives maximum signal and (f) the third lowest frequency f_(max.3)that gives maximum signal?