# What is the discontinuity of the function #f(x) = (x^2-3x-28)/(x+4)# ?

##### 1 Answer

If a rational expression (basically a fraction with a polynomial in the numerator and another polynomial in the denominator) has a discontinuity, it will be where the denominator equals zero.

So for

or

Now there are two types of discontinuity possible here.

If

If

Let's see:

*x* doesn't equal

The discontinuity is removable. The graph would look like the line

Note that most graphers will not properly show a hole (as in this case); this is known as a graphing error.