SOLUTION: What are the first four terms of the following sequence: a[n]=(-3)^n n for >= 1 a) 0,-3,18,-81 b) -3,18,-81,324 c) 3,18,81,324 d) 18, -81, 324, -1215

Algebra ->  Average -> SOLUTION: What are the first four terms of the following sequence: a[n]=(-3)^n n for >= 1 a) 0,-3,18,-81 b) -3,18,-81,324 c) 3,18,81,324 d) 18, -81, 324, -1215      Log On


   

Question 880878: What are the first four terms of the following sequence: a[n]=(-3)^n n for >= 1
a) 0,-3,18,-81
b) -3,18,-81,324
c) 3,18,81,324
d) 18, -81, 324, -1215
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
n=1,a%5B1%5D=%28-3%29%5E1=-3
n=2,a%5B2%5D=%28-3%29%5E2=9
n=3,a%5B3%5D=%28-3%29%5E3=-27
n=4,a%5B4%5D=%28-3%29%5E4=81.
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Is your sequence correct?
a%5Bn%5D=%28-3%29%5En
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Is it a%5Bn%5D=n%2A%28-3%29%5En???
If so then,
n=1,a%5B1%5D=1%2A%28-3%29%5E1=1%2A-3=-3
n=2,a%5B2%5D=2%2A%28-3%29%5E2=2%2A9=18
n=3,a%5B3%5D=3%2A%28-3%29%5E3=3%2A-27=-81
n=4,a%5B4%5D=4%2A%28-3%29%5E4=4%2A81=324