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If f(1) = 2 and f(n) = f(n − 1)^2 + 3 then find the value of f(3).

User Wdtj
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1 Answer

5 votes

Answer: 52

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Step-by-step explanation:

Let's use the recursive rule to find f(2)

We'll plug n = 2 into the second equation to find that...

f(n) = ( f(n-1) )^2 + 3

f(2) = ( f(2-1) )^2 + 3

f(2) = ( f(1) )^2 + 3

f(2) = ( 2 )^2 + 3

f(2) = 4 + 3

f(2) = 7

Notice in the jump from lines 3 to 4, we go from f(1) to 2. So f(2) is dependent on what f(1) is.

In other words, the second term is dependent on the first term.

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Likewise, f(3) is dependent on f(2)

Plug n = 3 into the recursive definition to find the following

f(n) = ( f(n-1) )^2 + 3

f(3) = ( f(3-1) )^2 + 3

f(3) = ( f(2) )^2 + 3

f(3) = ( 7 )^2 + 3

f(3) = 49 + 3

f(3) = 52

The third term of this recursive sequence is 52.

User Marco Vos
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