What is the recursive of this:

Step-by-step explanation:

Recursive Sequence

We are given the following sequence:

-1, 1, 5, 13...

It's required to find the recursive term for the sequence.

A recursive formula calculates each term as a function of one or more previous terms.

To find the recursive formula, we must find a pattern and transform it into a math expression.

Let's write the sequence, and below it, the difference of consecutive terms:

-1,   1,   5,   13...

+2,  +4,  +8

Note the difference between consecutive terms is always a power of 2, starting from 2^1, 2^2, 2^3.

The exponent is one less than the number of the term, thus:

Thus:

Testing:

n=1

(given).

n=2

n=3

n=4

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8