Answer:
[tex]a_n=\frac{1}{2}a_{n-1}[/tex]
Step-by-step explanation:
Here, you can see every consecutive term is divided by 2. I think that's pretty obvious looking at it, but you can work it out like this if you'd like to. Divide each consecutive term by the one before it:
[tex]6\div12=\frac{1}{2}\\\\3\div6=\frac{1}{2}\\\\\frac{3}{2}\div3=\frac{1}{2}[/tex]
Each term is multiplied by 1/2 over the last, or divided by 2. In this case actually, we do want it in the form of "multiplied by 1/2", as the recursive equation is:
[tex]a_n=xa_{n-1}[/tex]
where x is the factor. Here, we're multiplying by x, so we want "multiplied by 1/2" as described above. x is 1/2, so you can write the equation:
[tex]a_n=\frac{1}{2}a_{n-1}[/tex]
You can simply interpret this as "each term is 1/2 of the term before it"