Question

What is the third term of the sequence? a1 = k an = 2an-1 2k 4k 6k 8k

Answer 1

Given, 

first term a₁ = k

General term;

$a_{n} = 2a_{n-1}$

Hence, third term (n = 3);

$a_{3} = 2 a_{3-1} = 2a_{2} = 2 * (2a_{2-1}) = 4a_{1} = 4k$

Hence, the answer is B: 4k.

Answer 2

Answer:

option 2nd is correct

4k is the third term of the sequence.

Step-by-step explanation:

Given the statement:

$a_1 = k$

$a_n = 2a_{n-1}$

We have to find the third term of the sequence.

For n = 2 we have;

$a_2= 2a_{2-1}$

⇒$a_2= 2a_{1}$

Substitute the given value we have;

$a_2 = 2 \cdot k = 2k$

For n =3,

$a_3= 2a_{3-1}$

⇒$a_3= 2a_{3}$

Substitute the given value of $a_2$ we have;

$a_3= 2 \cdot 2k = 4k$

Therefore, the third term of the sequence is, 4k