Question

F(n)=5.(-2)n-1
Complete the recursive formula of f(n).​

Answer 1

first =a(1)=5
second=a(n)=-2

Explanation:

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Answer 2

a(n) =
`(-2)(a_(n-1))`

`a_(1)=5`

Explanation:

The given expression is in the form of the explicit formula of a geometric sequence.

f(n) =
`a(r)^(n-1)`

Where 'a' = First term of the sequence

r = common ratio

Recursive formula of a geometric sequence is,

a(n) =
`(a_(n-1)).(r)^(n-1)`

a(n) =
`(-2)(a_(n-1))`

Where,
`a_(1)=5`

So the recursive formula will be a(n) =
`(-2)(a_(n-1))`