Advertisements
Advertisements
प्रश्न
Which term of the AP: 53, 48, 43,... is the first negative term?
उत्तर
Given AP is 53, 48, 43,...
Whose first term (a) = 53 and
Common difference (d) = 48 – 53 = –5
Let nth term of the AP be the first negative term.
i.e., Tn < 0 ...[∵ nth term of an AP, Tn = a + (n – 1)d]
⇒ [a + (n – 1 )d] < 0
⇒ 53 + (n – 1)(– 5) < 0
⇒ 53 – 5n + 5 < 0
⇒ 58 – 5n < 0
⇒ 5n > 58
⇒ n > 11.6
⇒ n = 12
i.e., 12th term is the first negative term of the given AP
∴ T12 = a + (12 – 1)d
= 53 + 11(–5)
= 53 – 55
= –2 < 0
APPEARS IN
संबंधित प्रश्न
How many three-digit numbers are divisible by 7?
Write the first five terms of the following sequences whose nth term are:
`a_n = (n - 2)/3`
Write the first five terms of the following sequences whose nth terms are:
`a_n = 3^n`
An A.P. consists of 60 terms. If the first and the last terms be 7 and 125 respectively, find the 32nd term.
The first term of an A.P. is 2 and the last term is 50. The sum of all these terms is 442. Find the common difference.
Find:
(ii) the 35th term of AP 20,17,14,11,..........
Find the nth term of the following Aps:
(i) 5, 11, 17, 23 …
The 11th term of the AP: `-5, (-5)/2, 0, 5/2, ...` is ______.
The nth term of an A.P. 5, 2, -1, -4, -7 … is ______.
Which term of the AP: 21, 42, 63, 84,... is 210?
