SOLUTION: Is it C? I want to check my answer. Which sequence could be described by the explicit definition: LaTeX: a_n=n^2-5a n = n 2 − 5 A. 1,-4,4,11,116,... B. 1,2,3,4,5,6,...

Algebra ->  Probability-and-statistics -> SOLUTION: Is it C? I want to check my answer. Which sequence could be described by the explicit definition: LaTeX: a_n=n^2-5a n = n 2 − 5 A. 1,-4,4,11,116,... B. 1,2,3,4,5,6,...       Log On


   



Question 1161296: Is it C? I want to check my answer.
Which sequence could be described by the explicit definition: LaTeX: a_n=n^2-5a n = n 2 − 5
A. 1,-4,4,11,116,...
B. 1,2,3,4,5,6,...
C. -4,-1,4,11,20,....
D. -4,11,116,13451

The question for the sequence and the question itself is provided in the link here: https://i.imgur.com/YXX1edt.png

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Answer: You are correct. The answer is C) -4, -1, 4, 11, 20

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Work Shown:

Plug in n = 1 to find the first term
a%5Bn%5D+=+n%5E2+-+5

a%5B1%5D+=+1%5E2+-+5

a%5B1%5D+=+1+-+5

a%5B1%5D+=+-4 is the first term

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Repeat for n = 2 to get the second term
a%5Bn%5D+=+n%5E2+-+5

a%5B2%5D+=+2%5E2+-+5

a%5B2%5D+=+4+-+5

a%5B2%5D+=+-1 is the second term

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Let n = 3 and we get...
a%5Bn%5D+=+n%5E2+-+5

a%5B3%5D+=+3%5E2+-+5

a%5B3%5D+=+9+-+5

a%5B3%5D+=+4 as the third term

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Let n = 4 and we get...
a%5Bn%5D+=+n%5E2+-+5

a%5B4%5D+=+4%5E2+-+5

a%5B4%5D+=+16+-+5

a%5B4%5D+=+11 as the fourth term

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And finally the fifth term is worked out below for n = 5
a%5Bn%5D+=+n%5E2+-+5

a%5B5%5D+=+5%5E2+-+5

a%5B5%5D+=+25+-+5

a%5B5%5D+=+20

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To summarize, we got the sequence -4, -1, 4, 11, 20, which matches with choice C.