Step-by-step explanation:
The given geometric sequence:
- 8, - 40, - 200, - 1000
Here, first term(a) = - 8, common ration(r) = [tex]\dfrac{-40}{-8}[/tex] = 5
To find, an explicit formula for the given geometric sequence = ?
We know that,
The explicit formula for the geometric sequence
[tex]a_{n} =ar^{n-1}[/tex]
∴ An explicit formula for the given geometric sequence
[tex]a_{n} =(-8)(5)^{n-1}[/tex]
[tex]a_{n} =\dfrac{-8}{5} (5)^{n}[/tex]
∴ An explicit formula for the given geometric sequence, [tex]a_{n} =\dfrac{-8}{5} (5)^{n}[/tex]
