1. The problem statement, all variables and given/known data A loudspeaker produces a musical sound by means of the oscillation of a diaphragm whose amplitude is limited to 0.9 µm. At what frequency is the magnitude a of the diaphragm's acceleration equal to g? 2. Relevant equations [tex]a=-\omega^2 x_m \cos(\omega t +\phi)[/tex] 3. The attempt at a solution I decided to chuck the cosine term overboard to see what happened... and I got the right answer (525.45 Hz)! Why am I allowed to maximize the cosine term if I'm not told that the diaphragm is constructed to maximize efficiency?