Advertisements
Advertisements
प्रश्न
Write an A.P. whose first term is a and common difference is d in the following.
Advertisements
उत्तर
a = –7, d = `1/2`
t1 = a = –7
t2 = a + d = `-7 + 1/2 = (-14 + 1)/2 = (-13)/2`
t3 = a + 2d = `-7 + 2(1/2)` = –7 + 1 = –6
t4 = a + 3d = `-7 + 3(1/2) = -7 + 3/2 = (-14 + 3)/2 = (-11)/2`
∴ A.P. is `-7, (-13)/2, -6, (-11)/2 .......`
∴ A.P. is –7, –6.5, –6, –5.5 ........
APPEARS IN
संबंधित प्रश्न
Find the sum of all numbers from 50 to 350 which are divisible by 6. Hence find the 15th term of that A.P.
If Sn1 denotes the sum of first n terms of an A.P., prove that S12 = 3(S8 − S4).
The first and the last terms of an AP are 7 and 49 respectively. If sum of all its terms is 420, find its common difference.
Show that a1, a2,..., an... form an AP where an is defined as below:
an = 3 + 4n
Also, find the sum of the first 15 terms.
If (m + 1)th term of an A.P is twice the (n + 1)th term, prove that (3m + 1)th term is twice the (m + n + 1)th term.
Find the sum of all odd numbers between 100 and 200.
What is the 5th term form the end of the AP 2, 7, 12, …., 47?
Find the sum of the following Aps:
9, 7, 5, 3 … to 14 terms
The sum of the first n terms of an AP is given by `s_n = ( 3n^2 - n) ` Find its
(i) nth term,
(ii) first term and
(iii) common difference.
Find the sum of all multiples of 9 lying between 300 and 700.
There are 25 rows of seats in an auditorium. The first row is of 20 seats, the second of 22 seats, the third of 24 seats, and so on. How many chairs are there in the 21st row ?
The 9th term of an A.P. is equal to 6 times its second term. If its 5th term is 22, find the A.P.
Q.4
Q.13
If an = 3 – 4n, show that a1, a2, a3,... form an AP. Also find S20.
For an A.P., If t1 = 1 and tn = 149 then find Sn.
Activitry :- Here t1= 1, tn = 149, Sn = ?
Sn = `"n"/2 (square + square)`
= `"n"/2 xx square`
= `square` n, where n = 75
The sum of all two digit odd numbers is ______.
The sum of all odd integers between 2 and 100 divisible by 3 is ______.
The sum of first five multiples of 3 is ______.
If sum of first 6 terms of an AP is 36 and that of the first 16 terms is 256, find the sum of first 10 terms.
