Advertisements
Advertisements
Question
If tn = 2n – 5 is the nth term of an A.P., then find its first five terms
Advertisements
Solution
tn = 2n – 5 ......[Given]
∴ t1 = 2(1) – 5 = 2 – 5 = – 3
t2 = 2(2) – 5 = 4 – 5 = – 1
t3 = 2(3) – 5 = 6 – 5 = 1
t4 = 2(4) – 5 = 8 – 5 = 3
t5 = 2(5) – 5 = 10 – 5 = 5
∴ The first five terms of A.P. are – 3, – 1, 1, 3, 5.
APPEARS IN
RELATED QUESTIONS
Find the sum of the following arithmetic series:
`7 + 10 1/2 + 14 + ....... + 84`
Decide whether the following sequence is an A.P., if so find the 20th term of the progression:
–12, –5, 2, 9, 16, 23, 30, ..............
Find the 19th term of the following A.P.:
7, 13, 19, 25, ...
Find the 27th term of the following A.P.
9, 4, –1, –6, –11,...
Six year before, the age of mother was equal to the square of her son's age. Three year hence, her age will be thrice the age of her son then. Find the present ages of the mother and son.
Select the correct alternative and write it.
What is the sum of first n natural numbers ?
Select the correct alternative and write it.
If a share is at premium, then -
For a given A.P. a = 3.5, d = 0, then tn = _______.
Find the 23rd term of the following A.P.: 9, 4,-1,-6,-11.
How many multiples of 4 lie between 10 and 205?
Choose the correct alternative answer for the following sub-question
If the third term and fifth term of an A.P. are 13 and 25 respectively, find its 7th term
Find tn if a = 20 आणि d = 3
Decide whether the given sequence 24, 17, 10, 3, ...... is an A.P.? If yes find its common term (tn)
12, 16, 20, 24, ...... Find 25th term of this A.P.
The nth term of an A.P. 5, 8, 11, 14, ...... is 68. Find n = ?
Find a and b so that the numbers a, 7, b, 23 are in A.P.
