Question

find a4 of the sequence whose nth term is given by an=(-1)n-1(5)n+1​

Answer 1

Step-by-step explanation:

Put n=4 in An

An= -4-20+1= -23

Answer 2

Answer:

The fourth term i.e. $a_{4}$ is -3125.

Step-by-step explanation:

The sequence is a collection of objects placed in order. There are four types of sequence arithmetic sequence, geometric sequence, quadratic sequence and special sequence.

We are provided with the general term of sequence which is

$\[{a_n} = {( - 1)^{n - 1}}{5^{n + 1}}\]$

Where n is a natural number from 1 to infinity.

The value of n is 4. Therefore, the fourth term is given by

$\[\begin{gathered} {a_n} = {( - 1)^{n - 1}}{5^{n + 1}} \hfill \\ {a_4} = {( - 1)^{4 - 1}}{5^{4 + 1}} \hfill \\ {a_4} = {( - 1)^3}{5^5} \hfill \\ {a_4} = - 3125 \hfill \\ \end{gathered} \]$

Therefore the fourth term $a_{4}$ is -3125.