Question

What is the explicit formula for the geometric sequence? 3, −18, 108, −648,....
(1 point)
Responses

An=3×−6(n−1)
cap A sub n is equal to 3 times negative 6 times open paren n minus 1 close paren

An=−6×3(n−1)
An=−6×3(n−1)

An=3×−6n−1
cap A sub n is equal to 3 times negative 6 raised to the n minus 1 power

An=−6×3n−1

Answer 1

The explicit formula is a_n = 3(−6)^(n−1).

(Reason: a1 = 3 and common ratio r = −18/3 = −6, so a_n = a1·r^(n−1).)