Prove that this series converges

[lom]

$$\sum \frac{e^{in\theta}}{\sqrt{n}}\\$$
using Abel law
?

 

[Mark44]

What have you tried. To get help in this forum, you need to show some attempt at a solution.

 

[HallsofIvy]

What is "Abel's law"?

You have posted four consecutive questions with showing any effort of your own. You should have read, in threads you are asked to read when you registered, that you must show what you have tried.