Determine whether the series is convergent or divergent

[Fatima Hasan]

Homework Statement

Homework Equations

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The Attempt at a Solution

Here's my work :

However , the correct answer is :

Can anyone tell me where's my mistake ?

 

[Orodruin]

Is this the full problem statement? You need to specify a value for $x$ to know whether the series converges or not. Furthermore, there really should be no $=$ inside your sum.

 

[Fatima Hasan]

Is this the full problem statement?

Yes.

 

[Orodruin]

Yes.

I am sorry, but it cannot be the full problem statement. A full problem statement is not just a sum without specifications of what goes inside it. Please reproduce the full problem statement exactly as given.