Determine whether the given sequence is arithmetic, geometric or neither. If the sequence is arithmetic, find the common difference; if the sequence is geometric, find the common ratio.

(1) {8 - 3n/4}

(2) {(5/4)^n}

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- Oct 24th 2008, 03:31 AMmagentaritaSequences
Determine whether the given sequence is arithmetic, geometric or neither. If the sequence is arithmetic, find the common difference; if the sequence is geometric, find the common ratio.

(1) {8 - 3n/4}

(2) {(5/4)^n}

- Oct 25th 2008, 01:04 AMCaptainBlack
For an arithmetic sequence there are constants $\displaystyle a$ and $\displaystyle b$ such that the $\displaystyle n$-th term can be written in the form:

$\displaystyle a+bn$

For a geometric sequence there are constants $\displaystyle a$ and $\displaystyle b$ such thatthe $\displaystyle n$-th term can be written in the form:

$\displaystyle ab^n$.

Now look at the two cases given in your question and you shound be able to answer this your self.

CB - Oct 25th 2008, 04:53 AMmagentaritaThanks...