Actually , expanding the integral is exactly what you do . The exponential has a well known series expansion , and the square term will give you only even terms . Then , integrating each term in that series will give you a good final form . You will also want to express the constant multiplier e as a series the exponential of 1 and multiply through . Then you will want to express the left side in a compatible way . The modified factorial or skip factorial or 2 sected has a well known expression in terms of normal factorials . Plug that in and you will see equality immediately . <| sep |> His ult is garbage . It ' s only very situationally useful . His R and EXQ are great though . He has a kit that allows him to do insane burst damage in 1 v 1 s if you ' re able to land your M 1 s reliably to incap .