Question

Given the explicit formula an=3(-4)n-1, what is the sixth term?

Answer 1

a6 = -3072

Explanation:

Put 6 where n is and do the arithmetic.

Since the form of your function looks like it is trying to describe a geometric sequence, we assume you actually mean ...

an = 3(-4)^(n-1)

So, for n=6, this has the value ...

a6 = 3(-4)^(6-1) = 3(-1024)

a6 = -3072

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Same deal if you really mean

an = -12n -1

a6 = -12(6) -1 = -73