Which term of the AP 117, 104, 91, 78,...… is its first negative term
Answers
Answered by
3
Answer:
11th
Step-by-step explanation:
Let the first negative be nth term. In APs,
nth term = a + (n - 1)d
In the question, d = 104 - 117 = - 13
The first negative term must be the first term to be less than 0. (-ve no. are always less than 0).
=> nth term < 0
=> a + (n - 1)d < 0
=> 117 + (n - 1)(-13) < 0
=> 117 - 13n + 13 < 0
=> 130 < 13n
=> 10 < n
As n is greater than 10,n must be 11(as n€W).
11th term is the first negative term of this AP.
Answered by
2
Step-by-step explanation:
ANSWER ______$✍️
Given sequence is 117, 104, 91, 78
First term (a) = 117
Common difference (d) = Second term – first term
- = 104 – 117
- = – 13
We know that, nth term = a + (n – 1)d
Then,
8th term = a + (8 – 1)d
- = 117 + 7(-13)
- = 117 – 91 = 26
∴ 8th term of the A. P. is 26
Hope this helps you
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