Convergence or Divergence of ∑ tan(1/k) for k=5

Join the discussion
Registration is free. Start your own thread to ask a follow-up.
2 replies · 1K views
cloveryeah
Messages
25
Reaction score
0

Homework Statement


∞
∑ tan(1/k)
k=5

show that it is convergent or divergent

Homework Equations

The Attempt at a Solution


i used ratio test, but it's equal to 1, it means no works...
i used divergence test, it equals to 0, no work too...
so what should i do? i don't know how to use comparision test to attempt this problem
 
Physics news on Phys.org
Use the result that if [itex]0 < x \leq \frac12\pi[/itex] then [itex]\sin x \geq \frac{2x}{\pi}[/itex] to show that [tex] \tan\left(\frac1k\right) \geq \frac{2}{\pi k}.[/tex]