1. **State the problem:** We want to analyze the rational function $$y = \frac{2x^2 - 4}{2x^4 - 5x^2 + 2}$$ to find points of exclusion (POEs), vertical asymptotes (VAs), zeros (x-intercepts), end behavior, and asymptote type.
2. **Factor numerator and denominator:**
- Numerator: $$2x^2 - 4 = 2(x^2 - 2)$$
- Denominator: $$2x^4 - 5x^2 + 2$$ can be seen as a quadratic in $x^2$. Let $u = x^2$, then denominator becomes $$2u^2 - 5u + 2$$.
3. **Factor denominator quadratic:**
We look for two numbers that multiply to $2 \times 2 = 4$ and add to $-5$. These are $-4$ and $-1$.
Rewrite denominator:
$$2u^2 - 4u - u + 2 = (2u^2 - 4u) - (u - 2) = 2u(u - 2) -1(u - 2) = (2u - 1)(u - 2)$$
Substitute back $u = x^2$:
$$2x^4 - 5x^2 + 2 = (2x^2 - 1)(x^2 - 2)$$
4. **Simplify the function:**
$$y = \frac{2(x^2 - 2)}{(2x^2 - 1)(x^2 - 2)}$$
Cancel common factor $x^2 - 2$:
$$y = \frac{\cancel{2}(\cancel{x^2 - 2})}{(2x^2 - 1)(\cancel{x^2 - 2})} = \frac{2}{2x^2 - 1}$$
5. **Points of Exclusion (POEs):**
POEs occur where the canceled factor equals zero:
$$x^2 - 2 = 0 \Rightarrow x = \pm \sqrt{2}$$
6. **Vertical Asymptotes (VAs):**
VAs occur where the denominator equals zero and is not canceled:
$$2x^2 - 1 = 0 \Rightarrow x^2 = \frac{1}{2} \Rightarrow x = \pm \frac{1}{\sqrt{2}} = \pm \frac{\sqrt{2}}{2}$$
7. **Zeros (x-intercepts):**
Zeros occur where numerator equals zero:
$$2 = 0$$ has no solution, so no zeros.
8. **End behavior:**
Degree numerator after simplification is 0 (constant 2), degree denominator is 2 (from $2x^2 - 1$).
As $x \to \pm \infty$, denominator grows large, so:
$$y \to \frac{2}{\infty} = 0$$
So horizontal asymptote is $y=0$.
9. **Asymptote type:**
- Vertical asymptotes at $x = \pm \frac{\sqrt{2}}{2}$
- Horizontal asymptote at $y=0$
**Summary:**
- POEs: $x = \pm \sqrt{2}$
- VAs: $x = \pm \frac{\sqrt{2}}{2}$
- Zeros: none
- End behavior: $y \to 0$
- Asymptotes: vertical at $x=\pm \frac{\sqrt{2}}{2}$, horizontal at $y=0$
Rational Function Analysis 050514
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