See Problem 51.

(a) Write, as a product of sines and/or cosines, the sound emitted when the # key is touched.

(b) Determine the maximum value of y.

(c) Graph the sound emitted when the # key is touched.

Data from problem 51

Please listen carefully; our menu has changed. On your touch-tone phone, press 1 for Sales, press 2 for Returns, etc.” For each number pressed a unique sound is produced. The sound produced is the sum of two tones, given by

where l and h are the low and high frequencies (cycles per second) shown on the illustration. For example, if you touch 7, the low frequency is l = 852 cycles per second and the high frequency is h = 1209 cycles per second. The sound emitted when you touch 7 is

Transcribed Image Text:

y = sin(2πlt) and y = sin(2Tht)