Question

Recursive pattern for 1,-2,4,-8,16

Answer 1

`\begin{cases}a_1 = 1\\a_(n) = -2*a_(n-1)\end{cases}`

Step-by-step explanation:

The first row of the answer is
`a_1 = 1` which means "the first term is 1". The subscript below the 'a' tells us which term number we're on. Another example is that
`a_2` is the second term,
`a_3` is the third term, and so on.

The nth term denoted as
`a_n` is found by multiplying -2 with the previous term
`a_(n-1)`. This has subscript (n-1).

The informal recursive template we can think of is:

nth term = -2*(previous term)