How do you find nth term rule for $-28,14,-7,7/2,-7/4,...$ ?

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Answer 1 · 2016-08-17T23:01:02

$a_n = -28(-1/2)^(n-1)$

$(-7)/14 = -1/2 " and " 14/(-28) = -1/2$

It is a GP with $a_1 =-28$ and Common ratio = $r =-1/2$

$a_n = ar^(n-1)$

$a_n = -28(-1/2)^(n-1)$

How do you find nth term rule for -28,14,-7,7/2,-7/4,...-28,14,-7,7/2,-7/4,...?