Which of the following are you most likely to write?
r = zip xs $ map sqrt xs
or
r = [(x, sqrt x) | x <- xs]
Sample code on the Internet seems to indicate that the former is more abundant and the preferred way.
I'd likely write
map (\x -> (x, sqrt x)) xs
If you prefer point-free, the above is equivalent to (after having imported Control.Monad and Control.Monad.Instances)
map (ap (,) sqrt) xs
Another alternative that hasn't yet been mentioned is
zipWith (,) xs (map sqrt xs)