6. Identify the recursive formula for the sequence 3, –15, 75, –375, . . .
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Answer:
first option
Step-by-step explanation:
There is a common ratio r between consecutive terms in the sequence, that is
r = - 15 ÷ 3 = 75 ÷ - 15 = - 375 ÷ 75 = - 5
The recursive formula allows a term in the sequence to be found by multiplying the previous term by r , thus
f(n) = - 5f(n - 1) if n > 1
with f(1) = 3 ← first term