2007-03-03 14:04:38 · 3 answers · asked by seth 1 in Science & Mathematics ➔ Mathematics
whoops, brainfart, that answer was way off, 1/3 is the correct answer, they've explained it well enough.
2007-03-03 14:17:04 · answer #1 · answered by Chubbs20 2 · 0⤊ 1⤋
You do not need to know "N".
(3^[N+1] + 3^[N-1]) = 3^[N-1]*(3^2 + 1)
(3^[N+2] + 3^N) = 3^N*(3^2 + 1)
You can cancel out the (3^2 + 1) ... which is 10... from the top and bottom.
You are left with 3^[N-1] / 3^N, which is another way of writing 1/3.
2007-03-03 22:18:45 · answer #2 · answered by Dave 6 · 0⤊ 0⤋
1/3 and no, you don't need n. Factor the numerator and demoninator to give you multiples of 3^n.
(3^[n+1] + 3^[n-1] ) = (3^n)*(3^1) + (3^n)*(3^(-1)) = (10 * 3^n) / 3
(3^[n+2] + 3^[n] ) = (3^n)*(3^2) + (3^n)*(3^0) = (10 * 3^n)
Therefore... (1/3)/1 = 1/3
2007-03-03 22:16:37 · answer #3 · answered by spark_chasr 1 · 0⤊ 0⤋