Written by the Fiveable Content Team โข Last updated September 2025
Written by the Fiveable Content Team โข Last updated September 2025
Definition
A function is discontinuous at a point if there is a sudden jump, break, or hole at that point in its graph. The function does not have a well-defined limit or the value of the function does not match the limit at that point.
5 Must Know Facts For Your Next Test
For a function f(x) to be continuous at x = c, $\lim_{{x \to c}} f(x)$ must exist and be equal to f(c).
There are three types of discontinuities: removable, jump, and infinite.
Removable discontinuity occurs when $\lim_{{x \to c}} f(x)$ exists but is not equal to f(c).
Jump discontinuity happens when $\lim_{{x \to c^-}} f(x) \neq \lim_{{x \to c^+}} f(x)$. The left-hand limit does not equal the right-hand limit.
Infinite discontinuity arises when the limits approach infinity as x approaches c from either side.