calculus - Why does this sequence not oscillate?

I'm confused on why this sequence converges to 0 rather than diverge because of an oscillating series, since the result would be negative if n is odd and positive if n is even

Edit for the downvote: I apologize that my question was simple, but I genuinely thought it through for a while and could not understand. I was hoping I could ask the smart and giving people in order to enlighten me.