Question

Determine if the sequence is arithmetic or geometric. Then find the next term in the sequence. Select all that apply. 1, -4, 16, -64, …
1. arithmetic
2. geometric
3. 128
4. 256

Answer 1

Hello,

$u_{1} =1\\\\ u_{2} =-4=1*(-4)= u_{1} *(-4)\\\\ u_{3} =16=(-4)*(-4)= u_{2} *(-4)\\\\ u_{4} =-64=16*(-4)= u_{3} *(-4)\\\\ u_{5} =(-64)*(-4)= 256=u_{4} *(-4)$
The sequence is geometric of ratio -4.

Answer 2 and 4 are good. others false