How do you find the next three terms in the geometric sequence 4, -2, 1, -, ... ?

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Answer 1 · 2015-11-08T21:13:37

The common ratio of this sequence is $- \frac{1}{2}$ $-1/2$ , so the sequence goes:

$4,-2,1,-1/2,1/4,-1/8,...$

Geometric sequences have a fixed ratio between successive pairs of terms. in the case of this sequence, the common ratio is:

$(-2)/4 = -1/2$ .

To find the next term in the sequence just multiply the previous term by the common ratio.

The general term of the sequence can be written:

$a_n = a_1 * r^(n-1)$

where $a_1$ is the first term and $r$ the common ratio.