Answer:
[tex]g(n) = 10 * 3^{n}[/tex]
Step-by-step explanation:
Given
See attachment for table
Required
Determine the explicit formula for the table
First, we need to check if the guppies increases at arithmetic progression or geometry progression.
For arithmetic progression:
We calculate the common difference (d)
[tex]d = g(n) - g(n-1)[/tex]
Take n as 1
[tex]d = g(1) - g(1-1)[/tex]
[tex]d = g(1) - g(0)[/tex]
From the table:
[tex]g(1) = 30\ \&\ g(0) = 10[/tex]
[tex]d = 30 - 10[/tex]
[tex]d = 20[/tex]
Take n as 2
[tex]d = g(2) - g(1)[/tex]
From the table:
[tex]g(1) = 30\ \&\ g(2) = 90[/tex]
[tex]d = 90 - 30[/tex]
[tex]d = 60[/tex]
The two differences are not equal. So, this
For geometry progression:
We calculate the common ratio (r)
[tex]r = \frac{g(n)}{g(n-1)}[/tex]
Take n as 1
[tex]r = \frac{g(1)}{g(1-1)}[/tex]
[tex]r = \frac{g(1)}{g(0)}[/tex]
From the table:
[tex]g(1) = 30\ \&\ g(0) = 10[/tex]
[tex]r = \frac{30}{10}[/tex]
[tex]r = 3[/tex]
Take n as 2
[tex]r = \frac{g(2)}{g(1)}[/tex]
From the table:
[tex]g(1) = 30\ \&\ g(2) = 90[/tex]
[tex]r = \frac{90}{30}[/tex]
[tex]r = 3[/tex]
The two ratios are equal.
So, the next step is to calculate the explicit formula using n term of a geometric progression.
Because the progression starts from 0, we make use of the following formula
[tex]g(n) = g(0) * r^{n}[/tex]
Substitute values for g(0) and r
[tex]g(n) = 10 * 3^{n}[/tex]
Hence:
The explicit formula is: [tex]g(n) = 10 * 3^{n}[/tex]
