Question

Which formula can be used to describe the sequence?

Answer 1

the second, a good way to check is to simple sub 0, 1, 2, 3 in for x and see if the answers are the same as the ones listed

Answer 2

The formula that can be used to describe the sequence is:

`f(x)=-3\cdot ((-1)/(5))^(x-1)`

Explanation:

We are given a sequence of numbers as:

`-3\ ,\ (3)/(5)\ ,\ (-3)/(25)\ ,\ (3)/(125)\ ,\ (-3)/(625)`

Hence, we could observe that the series is a series with alternating sign such that the power of 5 is increasing in the denominator and there is no change in the numerator i.e. the power of 3 remain unchanged.

Hence,third and last option are discarded.

Also, in first option each of the terms of the digit will be negative and not alternating and hence option (1) is also discarded.

Hence, the function that represent this sequence is:

`f(x)=-3\cdot ((-1)/(5))^(x-1)`