• Support PF! Buy your school textbooks, materials and every day products Here!

Series homework problem help

  • Thread starter lha08
  • Start date
  • #1
164
0

Homework Statement


Using Comparison test and LCT, determine whether it is convergent or divergent:

(summation n=1 to infinity) sqrt(n+2)/(2n^2+n+1)



Homework Equations





The Attempt at a Solution


i compared it with sqrt(x)/2n^2 which is 1/2n^(3/2)
and then the answer showed something weird...they had to plug in a number (e.g. 1) which reversed the inequality sign... to sqrt(n+2)/(2n^2+n+1) is larger than 1/2n^(3/2)...does anyone know why?
 

Answers and Replies

  • #2
Dick
Science Advisor
Homework Helper
26,258
618


Then pick a different comparison. You want to make the numerator larger and the denominator smaller if you think it converges. Be creative! How about comparing with sqrt(n+n)/(2n^2)?
 

Related Threads for: Series homework problem help

  • Last Post
Replies
4
Views
7K
  • Last Post
Replies
2
Views
3K
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
2
Views
1K
Replies
4
Views
1K
  • Last Post
Replies
4
Views
888
  • Last Post
Replies
9
Views
7K
Top