Answer
(a) $4$
(b) $3$
(c) Does not exist.
Work Step by Step
(a) Graph the functions as shown, as $x\to -1^-, f(x)\to 4$, $$\lim_{x\to-1^-}f(x)=4$$
(b) As $x\to -1^+, f(x)\to 3$, $$\lim_{x\to-1^+}f(x)=3$$
(c) Because $$\lim_{x\to-1^-}f(x)\ne \lim_{x\to-1^+}f(x)$$ $$\lim_{x\to-1}f(x)$$ does not exist.
