Tristana is a very strong champion if you know how to play with it. She haves much attack damage. So that is why you need much attack speed, so u can hit much and fast. Here is a tip you cn use with Tristana:

-Use Rocket Jump to jump behind the enemie and use Buster Shot on them. They will be pushed to you`re teammates (if you want to kill someone with your team).

Tristana can also escape. Use Rocket Jump to jump away from your enemie.