It's an alternating sequence, beginning with the second term, so something probably happened (when n=1) that changed the sign of the first term.not an alternating negative, since 1/3 isn't [negative]
Your grouping symbols (shown in red above) are not correct; they need to enclose the entire numerator. See the last line, in this post.I found the sequence
(n^2)-2 / 3^n This is part of it. Good job.
Things are not always as they appear to be.I don't know how to handle the alternating part Yes you do!
How did you confirm that the following does not work?[This does not work:] (-1)^n
4bot already stated that this is an alternating sequence starting with the 2nd term.I found the sequence
(n^2)-2 / 3^n
However I don't know how to handle the alternating part
the sign pattern is,
+,+,-,+,-,+
So neither
(-1)^n
or
(-1)^n-1 or (-1)^n+1 work
Or, we could say:...your answer is 1/3 + (sigma from 2 to infinity)(-1)^n * (n^2 - 2) / 3^n