Comment by siraben

Why not translate your code to pointfree style automatically? Using[0], you can go from

  quad a b c = let d = b * b - 4 * a * c in ((-b + sqrt d) / 2 * a, (-b - sqrt d) / 2 * a)

to

  ghci> import Control.Monad
  ghci> quad = ap (ap . ((.) .) . ap (ap . (liftM2 (,) .) . flip (flip . ((*) .) . flip flip 2 . ((/) .) . (. sqrt) . (+) . negate)) (flip (flip . ((*) .) . flip flip 2 . ((/) .) . (. sqrt) . (-) . negate))) (flip ((.) . (-) . join (*)) . (*) . (4 *))
  ghci> quad 1 3 (-4)
  (1.0,-4.0)

[0] https://pointfree.io/