SOLUTION: If 𝑓(1) = 3 and 𝑓(𝑛) = −2𝑓(𝑛 − 1) + 1, then 𝑓(5) = A. -5 B. 11 C. 21 D. 43

Algebra ->  Sequences-and-series -> SOLUTION: If 𝑓(1) = 3 and 𝑓(𝑛) = −2𝑓(𝑛 − 1) + 1, then 𝑓(5) = A. -5 B. 11 C. 21 D. 43      Log On


   



Question 1049963: If 𝑓(1) = 3 and 𝑓(𝑛) = −2𝑓(𝑛 − 1) + 1,
then 𝑓(5) =
A. -5
B. 11
C. 21
D. 43

Found 2 solutions by stanbon, advanced_Learner:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
If 𝑓(1) = 3 and 𝑓(𝑛) = −2𝑓(𝑛 − 1) + 1,
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f(1) = 3
f(2) = -2*3+1 = -5
f(3) = -2*-5+1 = 11
f(4) = -2*11+1 = -21
f(5) = -2(-21)+1 = 43
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Cheers,
Stan H.
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then 𝑓(5) =
A. -5
B. 11
C. 21
D. 43

Answer by advanced_Learner(501) About Me  (Show Source):
You can put this solution on YOUR website!
n=1
f%281%29=3 first term is 3.
n=2

f%28n%29=-2f%28n-1%29%2B1
f%282%29=-2f%281%29%2B1
f%282%29=-2%2A%283%29%2B1
f%282%29=-5
n=3
f%283%29=-2f%282%29%2B1
f%283%29=11
n=4

f%284%29=-2f%283%29%2B1
f%284%29=-21
n=5

f%285%29=-2f%284%29%2B1
f%285%29=43