How do you find jump discontinuity?

1 Answer
Sep 5, 2014

There are 2 ways, you can look at a graph or you can use the definition.

Using the definition, show:

lim_(x->a^-)f(x)!=lim_(x->a^+)f(x) and both are finitie

It is important that they are finite. If one is not finite or does not exist, then it would be infinite discontinuity.

Using a graph, it's the same thing; both the red and blue functions have jump discontinuity:
enter image source here

Let's say the red function, f, is discontinuous at a and the blue, g, at b. Notice:

lim_(x->a^-)f(x)!=lim_(x->a^+)f(x) and f(a) DNE
lim_(x->b^-)g(x)!=lim_(x->b^+)g(x) and lim_(x->b^-)g(x)= g(b)