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For the infinite sequence a1, a2, ..., an, the value of an is the sum

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For the infinite sequence a1, a2, ..., an, the value of an is the sum  [#permalink]

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New post 17 Jan 2018, 00:15
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Question Stats:

52% (02:11) correct 48% (02:12) wrong based on 73 sessions

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For the infinite sequence \(a_1\), \(a_2\), ..., \(a_n\), the value of \(a_n\) is the sum of all previous terms in the sequence from \(a_1\) through \(a_{n−1}\), inclusive. If \(a_n=x\) and \(n>2\), which of the following expresses \(a_{n+2}\) in terms of x?

A. x+2

B. 2x

C. 3x

D. 4x

E. 8X

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Re: For the infinite sequence a1, a2, ..., an, the value of an is the sum  [#permalink]

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New post 17 Jan 2018, 00:26
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an=x=a1+a2+...a(n-1)
a(n+1)=a1+a2+...+a(n-1)+an=x+x=2x
a(n+2)=a1+a2+...+a(n-1)+an+a(n+1)=x+x+2x=4x

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Re: For the infinite sequence a1, a2, ..., an, the value of an is the sum   [#permalink] 17 Jan 2018, 00:26
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For the infinite sequence a1, a2, ..., an, the value of an is the sum

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