When a key is pressed on a touch-tone telephone, the keypad generates two pure tones, which combine to produce a sound that uniquely identifies the key. The figure shows the low frequency f1 and the high frequency f2 associated with each key. Pressing a key produces the sound wave y = sin(2rf3t) + sin(2rf2t). High frequency f2 1209 1336 1477 Hz 697 Hz 2 3 Low 770 Hz - 6. frequency 852 Hz - 8. 9. 941 Hz (a) Find the function that models the sound produced when the 9 key is pressed. y = sin(1704rt) + sin( 2954rt) (b) Use a Sum-to-Product Formula to express the sound generated by the 9 key as a product of a sine and a cosine function. y =

Evaluate the expression without using a calculator: (sin(π/3)cos(π/4)-sin(π/4)cos(π/3))2

Which of the following statements correctly describes the waveform corresponding to this frequency spectrum? Amplitude 5V Tu 0.5 kHz Frequency A sinusoidal signal with a frequency of 2 kHz and an amplitude of 7.5 V. A complex signal with a frequency of 1 kHz and an amplitude of 2.5 V. A sinusoidal signal with a frequency of 0.5 kHz and an amplitude of 2.5 V, plus a sinusoidal signal with a frequency of 1.5 kHz and an amplitude of 5 V. O A sinusoidal signal with a frequency of 0.5 kHz and an amplitude of 2.5 V and a third harmonic. 1.5 kHz

A Ferris wheel has a diameter of 50 m and the center of the wheel is 28 m off the ground. It rotates once every 90 seconds. Write a sine function that represents the height of a passenger. 5.