Which one of the following conditions is both necessary and sufficient for the…

MATHEMATICS · Single correct · AP · Calculus AB · Limits and Continuity · Limits and Continuity

Problem

Which one of the following conditions is both necessary and sufficient for the existence of

\displaystyle \lim_{x\to a}f(x)

? (a)

f

is continuous at

x=a

(b) Either the left-hand limit or the right-hand limit exists (c) Both one-sided limits exist and are equal (d) Both one-sided limits exist