Question

What is the rescursive formula for this geometric sequence? 7, -14, 28, -56

Answer 1

What is the recursive rule for a geometric sequence? It is this one:

an = an-1*r(I inserted a pic so you know how it actually looks like)
The sequence is 7, -14, 28, -56

To find r you divide the 2nd term by the first one. Then the third one by the second one. And so on. When you do this you will find that r= -2. All you have to do for the recursive rule is plug in r. So the formula for the sequence is

Answer 2

well, from looking at the numbers listed, they’re all multiplied by -2, (negative two) and so on, as you go through the number sequence.