Question

find the 4 term of the sequence (recursive) a1= 12
an=1/2 an-1

Answer 1

\[\Large\rm a_1=12\]\[\Large\rm a_n=\frac{1}{2}a_{n-1}\]

So it looks like each term will be half as large as the previous term.\[\Large\rm a_2=\frac{1}{2}a_{2-1}\]\[\Large\rm a_2=\frac{1}{2}a_{1}\]\[\Large\rm a_2=\frac{1}{2}\cdot 12\]
\[\Large\rm a_2=6\]

Answer 2

Understand how that process works? :o
Just cut that number in half a couple more times in order to find the `fourth` term.