Given that a geometric sequence can be expressed as a non-linear function in the form f(x) = abx, write a non-linear function to describe the sequence {3, 6, 12, 24, 48, 96, ...}.

Respuesta :

5naka

[tex]f(x) = 3 \times {2}^{x} [/tex]

Answer:

[tex]f(x)=\dfrac{3}{2}(2)^x[/tex]

Step-by-step explanation:

The given sequence is

{3, 6, 12, 24, 48, 96, ...}

It means f(x)=3, 6, 12, 24, 48, 96, ... for x=1,2,3,4,5,6,.. respectively.

We need to find non-linear function in the form  

[tex]f(x)=ab^x[/tex]       ...(1)

We know that f(x)=3 for x=1.

[tex]3=ab^1[/tex]          ....(i)

We know that f(x)=6 for x=2.

[tex]6=ab^2[/tex]          ....(ii)

Divide equation (ii) by (i).

[tex]\dfrac{6}{3}=\dfrac{ab^2}{ab}[/tex]

[tex]2=b[/tex]

Substitute b=2 in equation (1).

[tex]3=a(2)^1[/tex]

[tex]\dfrac{3}{2}=a[/tex]

Substitute [tex]a=\dfrac{3}{2}[/tex] and [tex]b=2[/tex] in (1).

[tex]f(x)=\dfrac{3}{2}(2)^x[/tex]

Therefore, the required function is [tex]f(x)=\dfrac{3}{2}(2)^x[/tex].