#1. check for common difference
-6-3 = -9; 12-(-6) = 18 ≠ -9 so not arithmetic
check for common ratio
-6/3 = -2; 12/-6 = -2 so the common ratio is -2; geometric
(assuming the ratio holds for the rest of the terms)
Now you try the others.
Please help describe the sequence as arithmetic geometric or neither. For arithmetic and geometric sequences give the common difference or common ratio.
1. {3,-6,12,-24,-48...}
2.{-11/4,-2,-5/4,-1/2,1/4...}
3.{3600,1440,576,230.4,...}
4.{600,-300,100,-25...}
1 answer