# Hi there, Please help me out with this math question! I am studying for my final exam, and I am stuck on these types of questions, so please explain the steps as well :) f(x) = x - 1 / 3x + 2 ;...

Hi there,

Please help me out with this math question! I am studying for my final exam, and I am stuck on these types of questions, so please explain the steps as well :)

f(x) = x - 1 / 3x + 2 ; find the non-permissible value of x.

### 1 Answer | Add Yours

I presume your expression is:

`f(x) = (x-1)/(3x+2)`

In this expression, x cannot be equal to -2/3 as this renders the denominator of the function equal to 0, and anything divided by zero is undefined.

As we can see from the graph of the function, as x approaches -2/3 the function goes to positive and negative infinity, but at no point is the function defined at x=-2/3. This is called an asymptote of a function, and in this case, it is a vertical asymptote.

**Sources:**