Respuesta :

Answer:

[tex]t(n)=12 \cdot 3^{n-1}[/tex]

Step-by-step explanation:

From inspection, the points on the graph are:

  • (1, 12)
  • (2, 36)
  • (3, 108)

Therefore, as terms of a sequence:

[tex]t_1=12\\\\t_2=36\\\\t_3=108[/tex]

The difference between the y-coordinates is not equal, therefore the sequence is geometric.

Geometric sequence formula: [tex]t_n=t_1r^{n-1}[/tex]

As [tex]t_1=12 \implies t_n=12r^{n-1}[/tex]

To find r, divide one term by the previous term:

[tex]r=\dfrac{t_3}{t_2}=\dfrac{108}{36}=3[/tex]

Therefore, geometric sequence formula: [tex]t_n=12 \cdot 3^{n-1}[/tex]