# Thread: Infinite series problem?

1. ## Infinite series problem?

Please help me for this problem.
Test the alternate series for absolute converges or conditionally converges or diverges.
∑(0 to ∞)(-1)^n [π/2 - arc tan(n)]

2. (i) u_n =( pi/2 - arctan n ) -> 0 as n -> +infty . (ii) u_n is decreasing. So, the series is convergent.

For the absolute convergence, compare u_n with v_n=1/n .