Respuesta :
Answer:
- r=3
- [tex]\left\{\begin{array}{ccc}a_1=-\frac{1}{9}\\a_n=-3a_{n-1}\end{array}\right[/tex]
Step-by-step explanation:
Given the sequence
[tex]-1/9, 1/3, -1, 3, -9, ...[/tex]
The common ratio is determined by the division of term by the previous term.
Common Ratio, [tex]r=\frac{1/3}{-1/9} =\frac{-1}{1/3} =\frac{3}{-1}=-3[/tex]
A recursive formula is a formula that defines each term of a sequence using preceding term(s).
For the given sequence, the recursive formula is:
[tex]\left\{\begin{array}{ccc}a_1=-\frac{1}{9}\\a_n=-3a_{n-1}\end{array}\right[/tex]
