Which sequence is modeled by the graph below?


coordinate plane showing the points 2, 1; 3, 3; and 4, 9


an = one third(27)n − 1


an = 27(one third)n − 1


an = one third(3)n − 1


an = 3(one half)n − 1

Verified Answer :

Answer:

the answer is C. an = one third (3)n − 1

i just took the test.

Step-by-step explanation:

Answer:

\(a_n=\dfrac{1}{3}\cdot (3)^{n-1}\)

C is correct.

Step-by-step explanation:

We need to choose correct model by the graph which passes through the points (2,1) (3,3) and (4,9)

Option 1: \(a_n=\dfrac{1}{3}\cdot (27)^{n-1}\)

Put n=2 and to get a₂=1

\(a_2=\dfrac{1}{3}\cdot (27)^{2-1}\)

\(a_2=9\)

\(9 eq 1\)

False

Option 2: \(a_n=27\cdot (\dfrac{1}{3})^{n-1}\)

Put n=2 and to get a₂=1

\(a_2=27\cdot (\dfrac{1}{3})^{2-1}\)

\(a_2=9\)

\(9 eq 1\)

False

Option 3: \(a_n=\dfrac{1}{3}\cdot (3)^{n-1}\)

Put n=2 and to get a₂=1

\(a_2=\dfrac{1}{3}\cdot (3)^{2-1}\)

\(a_2=1\)

\(1= 1\)

TRUE

Similarly, we will check (3,3) and (4,9)

and we will get true

Hence, The sequence is \(a_n=\dfrac{1}{3}\cdot (3)^{n-1}\)