Question

Find an explicit formula for the arithmetic sequence -11, -3, 5, 13, ...

Answer 1

Answer:

$a_{n}$ = 8n - 19

Step-by-step explanation:

The explicit formula for an arithmetic sequence is

$a_{n}$ = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = - 11 and d = - 3 - (- 11) = - 3 + 11 = 8, thus

$a_{n}$ = - 11 + 8(n - 1) = - 11 + 8n - 8 = 8n - 19

Answer 2

Answer:

$a_{n} = 8n-19$

Step-by-step explanation:

Explicit formula is :

$a_{n} = a_{1} + d(n-1)$

Where $a_{1}$ is the first element i.e. -11

and d is the difference between the elements i.e. 8

$a_{n} = -11 + (8)(n-1)$

$a_{n} = -11 + 8 (n-1)$

$a_{n} = -11+8n-8$

$a_{n} = 8n-19$