Sunday, September 24, 2017

a_n = nsin(1/n) Determine the convergence or divergence of the sequence with the given n'th term. If the sequence converges, find its limit.

a_n=nsin(1/n)
Apply n'th term test for divergence, which states that, 
If lim_(n->oo) a_n!=0 , then sum_(n=1)^ooa_n diverges
lim_(n->oo)nsin(1/n)=lim_(n->oo)sin(1/n)/(1/n)  
Apply L'Hospital's rule,
Test L'Hospital condition:0/0
=lim_(n->oo)(d/(dn)sin(1/n))/(d/(dn)1/n) 
=lim_(n->oo)(cos(1/n)(-n^(-2)))/(-n^(-2))
=lim_(n->oo)cos(1/n)
lim_(n->oo)1/n=0
lim_(u->0)cos(u)=1 
By the limit chain rule,

=1!=0 
So, by the divergence test criteria series diverges.  

No comments:

Post a Comment

Summarize the major research findings of "Toward an experimental ecology of human development."

Based on findings of prior research, the author, Bronfenbrenner proposes that methods for natural observation research have been applied in ...