Question

Find the value of the term in the arithmetic sequence using an = a^1+ (n-1)d. 3,5,7,9,11, (8th term)

Answer 1

Answer:  17

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Work Shown:

a1 = 3 = first term

d = 2 = common difference (since we add 2 to each term to get the next one)

Let's compute the nth term.

an = a1 + (n-1)*d

an = 3 + (n-1)*2

an = 3 + 2n-2

an = 2n+1

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To check things so far, we can plug in something like n = 2

an = 2n+1

a2 = 2*2+1

a2 = 5

Showing that the 2nd term is 5, which matches with the sequence given to us

Let's check n = 3

an = 2n+1

a3 = 2*3+1

a3 = 7

That matches as well. I'll let you check the others.

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Plug in n = 8 to find the 8th term

an = 2n+1

a8 = 2*8+1

a8 = 17

The eighth term is 17, which is the final answer.

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You could extend out the given sequence by adding 2 each time until you reach the 8th term

3,5,7,9,11,13,15,17

Though this method is slow if you need to find say the 38th term

Answer 2

Answer:

17 is the answer for the value of the term in the arithmetic sequence using the above