How to deal with ragers

Be nice. Ask them "please calm down" instead of saying "stfu". But the greatest moment was when their Diana killed me. I was under the mid inner turret and he was in the bush when she jumped on me and killed me, But she missed her Q so it took her about 3 secs. After that, she went on Graves and he flashed and healed. His heal would have saved me and i pointed that out nicely. From that point, he didn't say anything bad in chat. 1 down, ~4 mil to go