Saturday, 3 January 2015

`a_n = sin(npi/6)` Determine whether the sequence with the given n'th term is monotonic and whether it is bounded.

Sine function is periodic function with period of `2pi.` 


This means that the given sequence will have 12 unique values (because `12cdot pi/6=2pi`) and these values will repeat cyclically, more precisely `a_n=a_(n+12),` `forall n in NN.` Therefore, we conclude that the given sequence is not monotonic


On the other hand, codomain of the sine function is `[-1,1]` so the sequence is obviously bounded.


Maximum terms of the sequence are `a_(3+12k)=1,` `k in ZZ,` while the minimum terms...

Sine function is periodic function with period of `2pi.` 


This means that the given sequence will have 12 unique values (because `12cdot pi/6=2pi`) and these values will repeat cyclically, more precisely `a_n=a_(n+12),` `forall n in NN.` Therefore, we conclude that the given sequence is not monotonic


On the other hand, codomain of the sine function is `[-1,1]` so the sequence is obviously bounded.


Maximum terms of the sequence are `a_(3+12k)=1,` `k in ZZ,` while the minimum terms are `a_(9+12k)=-1,` `k in ZZ.`


The image below shows the first 60 terms of the sequence. We can clearly see the periodic nature of the sequence.                                                                  


No comments:

Post a Comment