Programming your calculator
18
DIFFLIST
Purpose
Find the first and second differences for a sequence.
Operation
Delete the contents of List 1 and then enter your sequence into List 1.
The program will store the first differences between elements of the sequence into List
2 and the second differences into List 3. Any data already in List 2 and List 3 will be lost.
Press (or ) to see the results of finding the differences.
To test the program, put the squares of the first ten integers (1, 4, 9, … , 100) into List 1.
When the program is activated, List 2 will show odd numbers and List 3 will show a
constant value of 2 (the difference between successive odd numbers).
When the second differences are constant, you can deduce that the original sequence is
quadratic.
Experienced programmers will be able to see how to modify the program so that third
differences are also calculated.
