1. **State the problem:** Find the inverse function $g^{-1}(x)$ of the one-to-one function $g(x) = \frac{4x}{5x - 9}$ and determine the domain and range of $g^{-1}$.
2. **Find the inverse function:**
Start with the equation:
$$y = \frac{4x}{5x - 9}$$
To find the inverse, swap $x$ and $y$:
$$x = \frac{4y}{5y - 9}$$
3. **Solve for $y$:**
Multiply both sides by the denominator to clear the fraction:
$$x(5y - 9) = 4y$$
Distribute $x$:
$$5xy - 9x = 4y$$
Bring all terms involving $y$ to one side:
$$5xy - 4y = 9x$$
Factor out $y$:
$$y(5x - 4) = 9x$$
Divide both sides by $(5x - 4)$:
$$y = \frac{9x}{5x - 4}$$
Show cancellation step:
$$y = \frac{9x}{\cancel{5x - 4}}$$
4. **Write the inverse function:**
$$g^{-1}(x) = \frac{9x}{5x - 4}$$
5. **Determine the domain of $g^{-1}$:**
The denominator cannot be zero:
$$5x - 4 \neq 0 \implies x \neq \frac{4}{5}$$
So the domain is:
$$(-\infty, \frac{4}{5}) \cup (\frac{4}{5}, \infty)$$
6. **Determine the range of $g^{-1}$:**
The range of $g^{-1}$ is the domain of $g$.
For $g(x) = \frac{4x}{5x - 9}$, the denominator cannot be zero:
$$5x - 9 \neq 0 \implies x \neq \frac{9}{5}$$
So the domain of $g$ (and range of $g^{-1}$) is:
$$(-\infty, \frac{9}{5}) \cup (\frac{9}{5}, \infty)$$
---
**Final answers:**
$$g^{-1}(x) = \frac{9x}{5x - 4}$$
Domain of $g^{-1}$: $(-\infty, \frac{4}{5}) \cup (\frac{4}{5}, \infty)$
Range of $g^{-1}$: $(-\infty, \frac{9}{5}) \cup (\frac{9}{5}, \infty)$
Inverse Function 2Ddcfb
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.