Answers:
- Neither
- Geometric
- Geometric
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Explanation:
The sequence {4,1,2} is neither because both arithmetic sequences and geometric sequence are either always increasing or always decreasing. We start off decreasing when going from 4 to 1, but increase to 2.
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The sequence {4,20,100} is geometric because we multiply each term by 5 to get the next term. That means the common ratio is 5. Notice how this sequence is increasing.
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The sequence {212,106,53} is also geometric. This time the common ratio is 1/2 = 0.5; this sequence is decreasing.
