Question

-What are the explicit equation and domain for a geometric sequence with a first term of 3 and a second term of −9?

an = 3(−12)n − 1; all integers where n ≥ 1

an = 3(−12)n − 1; all integers where n ≥ 0

an = 3(−3)n − 1; all integers where n ≥ 1

an = 3(−3)n − 1; all integers where n ≥ 0

Answer 1

@iPwnBunnies

Answer 2

please help

Answer 3

well with a 1st term 3 the common ratio would appear to be r = -3

becuase 3 x -3 = -9

the standard from of the equation is


\[a_{n} = a_{1} \times r^{n - 1}\]

so the 1st term is the clue.... 3 1st means n >= 1

and you know r = -3 so substituting you get

\[a_{n} = 3 \times(-3)^{n - 1}\]

hope it helps

Answer 4

so if you had to pick a answer which one would it be @campbell_st

Answer 5

well I thought my answer was rather obvious as to which is the correct answer.

Answer 6

@campbell_st so it would most likely be C

Answer 7

that's most likely right

Answer 8

ok @campbell_st thanks