Question

Find the first six terms of the sequence.

a1 = 4, an = an-1 + 8

OPTIONS ARE
a. 0, 8, 16, 24, 32, 40
b. 12, 20, 28, 36, 44, 52
c. 4, 12, 20, 28, 36, 44
d. 4, 8, 16, 24, 32, 40

Answer 1

(C) 4, 12, 20, 28, 36, 44

Explanation:

Given:
`a_(1)=4` and
`a_(n)=a_(n-1)+8`

To find: Find the first six terms of the sequence

Solution: Since, it is given that
`a_(1)=4` and
`a_(n)=a_(n-1)+8`, then the first term is 4 and the common difference, d=8.

Thus, the next terms are:

`a_(2)=a_(1)+8=4+8=12`,

`a_(3)=a_(2)+8=12+8=20`,

`a_(4)=a_(3)+8=10+8=28`,

`a_(5)=a_(4)+8=28+8=36` and

`a_(6)=a_(5)+8=36+8=44`

Thus, the first six terms of the sequence will be 4, 12, 20, 28, 36, 44.

thus, option C is correct.

Answer 2

The arithmetic sequence:
a 1 = 4, a n = a n-1 + 8, d = 8
a 2 = 4 + 8 = 12
a 3 = 12 + 8 = 20
a 4 = 20 + 8 = 28
a 5 = 28 + 8 = 36
a 6 = 36 + 8 = 44
Answer:
C ) 4, 12, 20, 28, 36, 44