Rational Root Analysis
1. **Stating the problem:** We analyze the function
$$f(x) = \frac{x}{2x^{2} - 3x + 1} + \sqrt{\frac{x-1}{1-2x}}$$
which consists of a rational function and a square root of a rational expression.
2. **Simplify the denominator of the rational function:**
The denominator is $$2x^2 - 3x + 1$$.
Factor it:
$$2x^{2} - 3x + 1 = (2x -1)(x -1)$$.
Therefore,
$$\frac{x}{2x^{2} - 3x + 1} = \frac{x}{(2x -1)(x -1)}$$.
3. **Analyze the domain restrictions from the rational function:**
The denominator cannot be zero:
\begin{align*}
(2x -1)(x -1) &\neq 0 \\
x &\neq \frac{1}{2}, \ x \neq 1
\end{align*}
4. **Analyze the square root term:**
$$\sqrt{\frac{x-1}{1-2x}}$$ requires the expression inside the root to be \(\geq 0\) and denominator \(\neq 0\).
We must have:
$$\frac{x-1}{1-2x} \geq 0$$
and
$$1-2x \neq 0 \Rightarrow x \neq \frac{1}{2}$$.
5. **Solve the inequality:**
Sign analysis on \(\frac{x-1}{1-2x}\) :
- Numerator zero at \(x=1\).
- Denominator zero at \(x=\frac{1}{2}\).
Intervals:
- For \(x < \frac{1}{2}\): denominator is positive (since \(1 - 2x > 0\))
- For \(x > \frac{1}{2}\): denominator negative
Check sign:
- When \(x < \frac{1}{2}\), numerator \(< 1\) and if \(x < 1\), numerator negative.
In \(( -\infty, \frac{1}{2} )\), numerator negative, denominator positive, so fraction negative \(<0\).
- In \(( \frac{1}{2}, 1 )\): numerator \(< 1\) positive (since \(x > 1/2\) but less than 1 means numerator negative), denominator negative, fraction \(\frac{negative}{negative} = positive\).
- At \(x=1\), numerator zero, fraction zero.
- For \(x > 1\), numerator positive, denominator negative, fraction negative.
So the inequality \(\geq 0\) holds in \([\frac{1}{2}, 1]\) except at \(x= \frac{1}{2}\) where denominator zero.
6. **Domain combined:**
From rational and root domain:
- Denominator of rational cannot be zero: \(x \neq \frac{1}{2}, 1\)
- Root expression nonnegative: \(x \in (\frac{1}{2},1]\)
Removing \(x=1\) from denominator, domain for root part compatible: \((\frac{1}{2}, 1)\)
Therefore, the function's domain is:
$$\boxed{\left(\frac{1}{2}, 1\right)}$$
7. **Summary:**
- The function is defined only on the open interval \((\frac{1}{2}, 1)\).
- The function combines a rational expression and a radical with a rational expression inside.
- Vertical asymptotes at \(x=\frac{1}{2}, 1\) due to zero denominators.
This detailed analysis aids in understanding the function behavior and domain restrictions.