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In a certain sequence, the first term is -4, and every term
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19 Apr 2018, 14:33
19 Apr 2018, 14:33
Expert Reply
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Question Stats:
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In a certain sequence, the first term is -4, and every term thereafter is defined by \(2 * |x| * \frac{1}{2}\), where x = preceding term. What is the sum of the first 300 terms?
A. It cannot be determined from the information given.
B. 0
C. 1186
D. 1192
E. 1200
A. It cannot be determined from the information given.
B. 0
C. 1186
D. 1192
E. 1200
In a certain sequence, the first term is -4, and every term
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Updated on: 17 Nov 2021, 16:31
Updated on: 17 Nov 2021, 16:31
1
First term is given as -4
The subsequent terms in the sequence can be obtained by applying the formula 2*|x|*1/2 where x is the previous term.
If you notice carefully, you will see that
2 *|x| * 1/2 is nothing but |x|
So,
the first term is -4
Second term is |-4| = 4
Third term is |4| = 4
Fourth term is |4| = 4
and so on....
So, the sequence here is
-4, 4, 4, 4, ................. 4 (total 300 terms)
The first two terms cancel out with each other. (-4 + 4 = 0)
We are now left with 298 terms, and all the terms are equal to 4
Sum of these would be 298 * 4 = 1192
Hope this helps
The subsequent terms in the sequence can be obtained by applying the formula 2*|x|*1/2 where x is the previous term.
If you notice carefully, you will see that
2 *|x| * 1/2 is nothing but |x|
So,
the first term is -4
Second term is |-4| = 4
Third term is |4| = 4
Fourth term is |4| = 4
and so on....
So, the sequence here is
-4, 4, 4, 4, ................. 4 (total 300 terms)
The first two terms cancel out with each other. (-4 + 4 = 0)
We are now left with 298 terms, and all the terms are equal to 4
Sum of these would be 298 * 4 = 1192
Hope this helps
Re: In a certain sequence, the first term is -4, and every term
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20 Apr 2018, 01:57
20 Apr 2018, 01:57
First term in the sequence is -4 and all other 299 terms are 4s
So 299*4 - 4
=1196-4
=1192
Hence the answer.
So 299*4 - 4
=1196-4
=1192
Hence the answer.
