Try the following SAT math question for the Revised SAT on domain of functions.

What is the domain of the function $f$, defined as $f(x)=\dfrac{x}{1+x^2}$ ?

- $\quad x \geq 0 $
- $\quad -1 \leq x \leq 1$
- $\quad \textrm{All real numbers}$
- $\quad \textrm{All real numbers except $-1$}$