import Data.Foldable

maxSquare :: (Ord a, Num a) => [(a -> a)] -> (a -> a)
maxSquare funcs = helper
    where helper x = snd $ maximumBy getMax (map makeTuples funcs)
            where makeTuples f = (f x * f x, f x)
                  getMax a b = compare (fst a) (fst b)


-- maxSquare :: (Ord a, Num a) => [(a -> a)] -> (a -> a)
-- maxSquare funcs = helper
--     where helper x = sqrt $ maximum (map getSquared funcs)
--           where getSquared f = f x * f x