Formulate the recursive formula for the following geometric sequence. {-16, 4, -1, ...}

Verified Answer :

each term is negative and 1/4 of previous term
so the nth term is the n-1 term times -1/4

so
\(f(n)= \frac{-1}{4} f(n-1)\)

Answer:

\(a_n=-\frac{1}{4} \cdot a_{n-1}\)

Step-by-step explanation:

The recursive formula for the geometric sequence is given by:

\(a_n = a_{n-1} \cdot r\)

where,

r is the common ratio terms.

Given the sequence:

-16, 4, -1, ...

This is a geometric sequence.

Here, \(a_1 = -16\) and \(r = -\frac{1}{4}\)

Since,

\(\frac{4}{-16} = -\frac{1}{4}\)

\(\frac{-1}{4} = -\frac{1}{4}\) ans so on .....

Substitute the given values we have;

\(a_n = a_{n-1} \cdot -\frac{1}{4} = -\frac{1}{4} \cdot a_{n-1}\)

⇒\(a_n = -\frac{1}{4} \cdot a_{n-1}\)

Therefore, the recursive formula for the following geometric sequence is, \(a_n = -\frac{1}{4} \cdot a_{n-1}\)