SOLUTION: Determine the general term for the following sequence: 1, -3, 9, -27. I came up with -3^n-1, which was marked wrong. Any insight would be much appreciated...

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Question 1086471: Determine the general term for the following sequence: 1, -3, 9, -27. I came up with -3^n-1, which was marked wrong. Any insight would be much appreciated...
Found 2 solutions by Boreal, MathTherapy:
Answer by Boreal(15235)   (Show Source): You can put this solution on YOUR website!
With these, make (-1)^(n) the sign changer then 3^n. That way, one can make the index n=0 to whatever value is desired.
-1^0*3^0
-1^1*3^1
-1^2*3^2
-1^3*3^3

Answer by MathTherapy(10552)   (Show Source): You can put this solution on YOUR website!

Determine the general term for the following sequence: 1, -3, 9, -27. I came up with -3^n-1, which was marked wrong. Any insight would be much appreciated...
 

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