Use the given graph of $ f $ to state the value of each quantity, if it exists. If it does not exist, explain why.
(a) $ \displaystyle \lim_{x\to 2^-}f(x) $
(b) $ \displaystyle \lim_{x\to 2^+}f(x) $
(c) $ \displaystyle \lim_{x\to 2}f(x) $
(d) $ f(2) $
(e) $ \displaystyle \lim_{x\to 4}f(x) $
(f) $ f(4) $