sin 11.' Exercise 6 Let Z on with an = 6' 7E kar, k integer. Prove that E on converges absolutely if a gt; 1. Prove that 2 an converges if 0...

Please help me within a few minutes ... Exercise related to convergence and divergence of series , analysis and calculus.

sin 11.3 to!"’ Exercise 6 Let Z on with an = 6' 7E kar, k integer. 1. Prove that E on converges absolutely if a > 1. 2. Prove that 2 an converges if 0 < o: S 1 (hint: after proving it, you can use theoos((n — 1/2)9) — cos((n+ 1/2)3) for 9 ¢ 211%). trigonometric formula. sin('n.6') = 2 sin(3/2) 3. Prove that E on diverges if or g 0.