Question

On a piano, a key has a frequency, say f0. Each higher key (black or white) has a frequency of f0 * rn, where n is the distance (number of keys) from that key, and r is 2(1/12). Given an initial key frequency, output that frequency and the next 4 higher key frequencies.

Output each floating-point value with two digits after the decimal point, which can be achieved as follows:
System.out.printf("%.2f", yourValue);

Ex: If the input is:

440.0

(which is the A key near the middle of a piano keyboard), the output is:

440.00 466.16 493.88 523.25 554.37

Note: Use one statement to compute r = 2(1.0/12.0) using the pow function. Then use that r in subsequent statements that use the formula fn = f0 * rn with n being 1, 2, 3, and finally 4.

Answer 1

import java.util.Scanner;

public class LabProgram {
   
   public static void printKeys(double inputKey) {
      
      double r = Math.pow(2.0, 1.0/12.0);
      double key;
      double n;
      
      for (n = 1.0; n <= 4; n++) {
         
         key = inputKey * Math.pow(r, n);
         
         System.out.printf(" %.2f", key);
         
      }
      
   }
   
   public static void main(String[] args) {
      
      double inputKey;
      
      Scanner scnr = new Scanner(System.in);
      
      inputKey = scnr.nextDouble();
      
      System.out.printf("%.2f", inputKey);
      
      printKeys(inputKey);
      
      System.out.print("\n");
      
   }
   
}

Answer 2

#Taking the n value as input

note=float(input("Please Enter the value of n: "))

#value of power is 2^(1/12)

power=2**(1/12)

frequency1=note*power

frequency2=frequency1*power

frequency3=frequency2*power

frequency4=frequency3*power

print("{:.2f} {:.2f} {:.2f} {:.2f} {:.2f}".format(note,frequency1,frequency2,frequency3,frequency4))