Question

find $a_4$.$a_1 = 2LXB0a_n = 3a_{n - 2}$write your answer as an integer or fraction in simplest form.$a_4 = $

Explanation:

Step1: Identify n for target term

We need $a_4$, so $n=4$.

Step2: Apply recurrence relation

Use $a_n = 3a_{n-2}$. Substitute $n=4$:
$a_4 = 3a_{4-2} = 3a_2$

Step3: Substitute known $a_2$ value

We know $a_2=5$, so:
$a_4 = 3 \times 5$

Answer:

15