Answer:
-7 * (1/3) ^ (n-1)
Explanation:
I think the question should be related to going from recursive to explicit form, therefore:
We have that the recursive formula for the given geometric sequence is:
a1 = -7
an = (an-1) * (1/3)
With the above we can assume that:
r = 1/43
following the rule of the explicit formula that is given by:
an = a1 * (r) ^ (n-1)
we substitute and we have:
an = -7 * (1/3) ^ (n-1)
Therefore the explicit formula from the given data would be:
an = -7 * (1/3) ^ (n-1)