Question

Sort the sequences according to whether they are arithmetic, geometric, or neither.

Answer 1

Answer:

• arithmetic
• neither
• geometric
• arithmetic
• geometric

Step-by-step explanation:

Arithmetic sequences have a common difference. Often, checking for that is the easiest. Geometric sequences have a common ratio. If there is neither a common difference nor a common ratio, then the sequence is not one of these types.

The difference or ratio refers to the relation of a term in the sequence to the one before it. For example, 94.1 -98.3 = -4.2. If the same difference exists for subsequent pairs of terms, then the difference is said to be "common." Likewise, 3.5/1.75 = 2. If the same ratio exists for subsequent pairs of terms, it is a "common" ratio.

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98.3, 94.1, ... -- arithmetic (common difference = -4.2)

1, 0, -1, 0, ... -- neither

1.75, 3.5, ... -- geometric (common ratio = 2)

-12, -10.8, ... -- arithmetic (common difference = -1.2)

-1, 1, ... -- geometric (common ratio = -1)