PLEASE HELP
find the first 5 terms in the sequence
A) 6, 12, 24, 48, 96
B)1, 2, 3, 4, 5
C)6, 7, 8, 9, 10
D) 6, 11, 21, 41, 81

PLEASE HELP find the first 5 terms in the sequence A 6 12 24 48 96 B1 2 3 4 5 C6 7 8 9 10 D 6 11 21 41 81 class=

Respuesta :

Answer:

The first five terms are 6, 11, 21, 41, 81 ⇒ D

Step-by-step explanation:

∵ The rule of the sequence is a(1) = 6; a(n) = 2 a(n - 1) - 1 for n ≥ 2

∴ The first term of the sequence is 6

∴ The value of n represents the position of the term

∵ n = 2

∴ a (n - 1) = a(2 - 1) = a1

∵ a1 = 6

→ Substitute a1 by 6

∴ a(2) = 2(6) - 1 = 12 - 1

a(2) = 11

∵ n = 3

∴ a (n - 1) = a(3 - 1) = a2

∵ a2 = 11

→ Substitute a2 by 11

∴ a(3) = 2(11) - 1 = 22 - 1

a(3) = 21

∵ n = 4

∴ a (n - 1) = a(4 - 1) = a3

∵ a3 = 21

→ Substitute a3 by 21

∴ a(4) = 2(21) - 1 = 42 - 1

a(4) = 41

∵ n = 5

∴ a (n - 1) = a(5 - 1) = a4

∵ a4 = 41

→ Substitute a4 by 41

∴ a(5) = 2(41) - 1 = 82 - 1

a(5) = 81

∴ The first five terms are 6, 11, 21, 41, 81