Final answer:
The frequency of the A1 note, which is three octaves lower than the A4 note with a frequency of 440 Hz, is 55 Hz.
Step-by-step explanation:
The A4 note has a frequency of 440 cps (cycles per second, also known as Hz). An octave in music is a doubling or halving of frequency, depending on whether you are moving up or down. Since A1 is three octaves lower than A4, we need to halve the frequency three times.
- From A4 to A3: 440 Hz / 2 = 220 Hz
- From A3 to A2: 220 Hz / 2 = 110 Hz
- From A2 to A1: 110 Hz / 2 = 55 Hz
Therefore, the frequency of the A1 note is 55 Hz.