Find the domain of the function `f(x)` defined by `f(x)=sqrt(4-x)+1/(sqrt(x^2-1))` .

Explanation

To find the domain of the function \( f(x) = \sqrt{4 - x} + \frac{1}{\sqrt{x^2 - 1}} \), we need to analyze the two parts of the function separately.

### Step 1: Analyze the first part \( \sqrt{4 - x} \)

For the square root function \( \sqrt{4 - x} \) to be defined, the expression inside the square root must be non-negative:

\[
4 - x \geq 0
...