The image you uploaded contains a mathematical problem in Persian. Here's a translation and breakdown of the content:

Problem:

We are given the following function:

$f(x) = \frac{x^3 + 3x}{x - 1}$

And the question is asking which of the following is the smallest value for $b - a$, where $a$ and $b$ are values for which the function is evaluated at two different points.

The provided options are:

1. 2
2. 4
3. 6
4. 8

Let me know if you'd like further clarification or help solving the problem!