My ex and I have a daughter who is 5 and we separated ever since she was about 11 months. Ever since then he started dating girls and I stayed single for about 3yrs. To make the story short I am now with someone and still not able to get along with my daughters dad. And honestly I tried to talk to him and tell him that I want for to get along and he just says no. I would want to know if I should keep on trying to get him to get along and I would want to know why of his behavior.

Dang?. thats stuff?

honestly I tried to talk to him and tell him that I want for to get along and he just says no.
Just curious what would that be?

I would want to know if I should keep on trying to get him to get along
Actually you don't have to be friends at all, but work together for your child. Keep it confined to that, and forget the friends stuff.

I would want to know why of his behavior.
He doesn't really like you for whatever reason. That's why your not together, and could be as simple as not being compatible.