1. **State the problem:** We have three functions:
A) $f(x) = \frac{x^2 - 1}{x}$
B) $f(x) = x \sqrt{x^2 - 1}$
C) $f(x) = x^2 - 1$
We need to determine which function intersects the first axis (x-axis) at points $x=1$ and $x=-1$ but does **not** intersect the second axis (y-axis).
2. **Analyze each function for x-intercepts:**
- The first axis (x-axis) is where $f(x) = 0$.
For A:
$$f(x) = \frac{x^2 - 1}{x} = \frac{(x-1)(x+1)}{x}$$
Setting $f(x)=0$ means numerator zero, denominator non-zero:
$$x^2 - 1 = 0 \implies x=1 \text{ or } x=-1$$
These are valid x-intercepts since denominator $x \neq 0$ at these points.
For B:
$$f(x) = x \sqrt{x^2 - 1}$$
Set $f(x)=0$:
$$x \sqrt{x^2 - 1} = 0$$
This is zero if either $x=0$ or $\sqrt{x^2 - 1} = 0$ which implies $x^2 - 1 = 0 \Rightarrow x = \pm 1$.
At $x= \pm 1$, $f(x)=0$.
For C:
$$f(x) = x^2 - 1$$
Set $f(x)=0$:
$$x^2 -1=0 \implies x=\pm 1$$
All three intersect x-axis at $x=\pm 1$ (except B also at 0).
3. **Analyze each function for y-intercepts:**
The second axis (y-axis) is at $x=0$, so compute $f(0)$ where defined:
For A:
$$f(0) = \frac{0^2 - 1}{0} = \frac{-1}{0}$$
Not defined, so no y-intercept.
For B:
$$f(0) = 0 \times \sqrt{0^2 - 1} = 0 \times \sqrt{-1}$$
Not real-valued; no y-intercept.
For C:
$$f(0) = 0^2 - 1 = -1$$
So, crosses y-axis at $y=-1$.
4. **Conclusion:**
- Only A and B do not have y-intercepts.
- All three have x-intercepts at $x=\pm 1$ (B also at 0 but that is extra).
Problem asks for function intersecting x-axis at $x=\pm 1$ and not intersecting y-axis.
Therefore, functions A and B satisfy the condition.
Since the question asks "Which of the following maps intersects the first axis $x=1$ and $x=-1$ but does not intersect the second axis?"
The best fit is **A) $f(x) = \frac{x^2 - 1}{x}$**, because it has x-intercepts at $\pm 1$ and is undefined at zero, so no y-intercept.
5. **Summary:**
- A) Intersects x-axis at $x=\pm 1$, no y-intercept.
- B) Intersects x-axis at $x=\pm 1$ and also at 0; no real y-intercept.
- C) Intersects both axes.
**Final answer:** Function A.
Axis Intersections
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