Sequences
Determine whether $$\left\{(-3)^n \right\}$$ is increasing, decreasing, or neither.
Steps:
a5 = (-3)^5 = -243
a6 = (-3)^6 = 729
a7 = (-3) ^7 = -2187
a8 = (-3)^8 = 6561
Answer = neither
(Note: The number next to "a" is actually smaller and below, I'm just not sure how to insert it.)
My question is how did they get neither? I'm still having trouble differentiating between increasing, decreasing, and neither.
+118723 As n increases the value goes back and forth between positive and negative.
So you cannot say that it is increasing or that it is decreasing. Does that make any more sense?
Thank you for asking us to clarify an answer - we like you to do that if you do not fully understand:)
+130511 Notice that when n is odd....then (-3)n is negative......and when n is even, (-3)n is even.....thus, as n increases (or decreases), (-3)n neither increases or decreases......it "oscillates" between "negative" and "positive"
How do they choose what goes into n? I mean how do you know to pick an odd or even sequence. Or neither? They chose 5, 6, 7, 8. When they asked in its original question format all it said was to give the following sequence and determine whether it's increasing, decreasing, or neither.
+118723 As n increases the value goes back and forth between positive and negative.
So you cannot say that it is increasing or that it is decreasing. Does that make any more sense?
Thank you for asking us to clarify an answer - we like you to do that if you do not fully understand:)
