An acoustic signal from a guitar is composed of the first three harmonics of a wave of fundamental frequency 451 Hz. If these harmonics are described, in order, by cosine waves with amplitudes of 0.42, 0.82, and 0.64, what is the total amplitude of the signal at time t = 0.371 s? Assume the waves have phase angles 8, = 0. Hint: Do not round numerical calculations early; particularly the arguments of the cosine functions. Either store terms in calculator memory or record on paper to add properly.