(04.06 LC) The first four terms of a sequence are shown below:
8, 5, 2, -1
Which of the following functions best defines this sequence? (5 points)
f(n) = - 3(n-1) +8; for n 2 1
O f(n) = 3(n-1) +8; for n 2 1
O f(n) = - 5(n-1) +8; for n 2 1
f(n) = 5(n-1) +8; for n 2 1

Given:

The first four terms of a sequence are:

8, 5, 2, -1

To find:

The function that defines the given sequence.

Solution:

We have,

8, 5, 2, -1

The differences between two consecutive terms are:

The given sequence has a common difference -3. It means the given sequence is an arithmetic sequence with first term 8 and common difference -3.

The nth terms of an arithmetic sequence is:

, for

Where, a is the first term and d is the common difference.

Putting , we get

, for

Therefore, the correct option is A.

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step-by-step explanation:

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