posted by Faith on .
Name the constant differences of the sequence 20, 21, 26, 35, 48...
What does "constant differences" mean?
Thank you so much! :)
suppose you subtract the second - first = 1
third - second = 5
fourth - third = 9
fifth - fourth = 13
to get the "first differences" of 1,5,9,13
now suppose we repeat the same procedure
5-1 = 4
9-5 = 4
13-9 = 4
notice we now have "constant differences" but we had to do it twice.
if the first differences are constant, then the data came from a first degree relation
if the second differences are constant, then the data came from a second degree, or quadratic relation
if the third ....
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