Find a formula that generates a sequence

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SUMMARY

The discussion focuses on deriving a formula for the sequence defined as 2/(3 x 4), -3/(4 x 5), 4/(5 x 6), -5/(6 x 7), etc. The proposed formula is a_n = -1(n/((n + 1)(n + 2))), which consistently produces negative values. To alternate the sign of the sequence, the suggestion to incorporate the term (-1)^n is presented as a viable solution, allowing for the desired pattern of negative and positive values.

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Homework Statement



Find a formula that generates the sequence:

2/(3 x 4), -3/(4 x 5), 4/(5 x 6), -5/(6 x 7), . . .

Homework Equations


The Attempt at a Solution



Here is what I have so far:

a_n = -1(n/((n + 1)(n + 2)))

Now, I'm stuck. The formula generates a negative number every time. I need a negative number every other time.
Any suggestions?
 
Last edited:
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Use something like (-1)^n?
 
Yeah, that will work. Thanks!
 

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