get tail of list haskell

list = [1, 2, 3, 4]

last [a] -> a
last [x] 	= x
last (_:xs) = last xs

last list -- 4

list = [1,2,3,4,5]
last list -- returns 5

list = [1, 2, 3, 4]

tail :: [a] -> [a]
tail [] = []
tail (_:xs) = xs