2016 Old Spec

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Question 5

The algorithm, represented using pseudo-code in Figure 4, and the variable table, Table 2, describe a program that outputs an estimate for a particular calculation.

Figure 4

OUTPUT "Enter a number:"
INPUT N
F = 16.0
IF N >= 1.0
  THEN
    X = N
    WHILE X * X – N > 1.0 AND F – 1.0 > 1.0 DO
      L = X
      X = X ÷ F
      WHILE X * X <= N DO
        F = F – 0.1
        X = L ÷ F
      ENDWHILE
    ENDWHILE
    OUTPUT X
  ELSE
    OUTPUT "Not a number greater than or equal to 1"
ENDIF

Table 2

Indentifier Data Type
X Real Number
F Real Number
L Real Number
N Real Number

What you need to do

  • Write a program for the algorithm in Figure 4.
  • Test the program by conducting the tests:
  1. Test that your program works correctly by entering the number 0.1
  2. Test that your program works correctly by entering the number 4.1