Question

The explicit rule for a sequence is an=7(−4)n−1 .

What is the recursive rule for the sequence?

A. an=−4(an+1),a1=7

B. an=−7(an+1),a1=4

C. an=−4(an−1),a1=7

D. an=−7(an−1),a1=4

Answer 1

to find a1, plug in n = 1 into an=7(−4)^(n−1)

then, to find an, it's an = [the common ratio]*(an−1)

[in this case, the common ratio is what's being given the exponent (n-1), (-4)

hope that isn't too confusing :S