Question

B) Solve the following:
1. Decide whether the following sequence is an A.P. or not 3,5,7,9,11​

Answer 1

Answer:

The given sequence is an Arithmetic progression

Step-by-step explanation:

given sequence 3,5,7,9,11​

=> 3, 3+1(2),3+2(2), 3+3(2),3+4(2)

each term is of the form a+(n-1)d

where a=3; and d = 2

and hence the given sequence is an Arithmetic progression

Answer 2

Solution!!

Sequence = 3, 5, 7, 9, 11

a = 3

d = 5 - 3 = 2, 7 - 5 = 2

Here, a → First term

d → Common difference between the terms

As we observe, the common difference between the consecutive terms of the sequence is same. Hence, we can conclude that the above sequence is an arithmetic sequence.

Formulae:-

To find the nᵗʰ term → aₙ = a + (n - 1)d

To find the sun of first n terms → Sₙ = n/2 (2a + (n - 1)d)

Let l be the last term. nᵗʰ term from the end → (l - (n - 1)d)