1. **State the problem:** Solve the inequality $$x^2 - 3x > \frac{1}{2}x^2 - 4$$.
2. **Rewrite the inequality:** Move all terms to one side to compare with zero.
$$x^2 - 3x - \frac{1}{2}x^2 + 4 > 0$$
3. **Combine like terms:**
$$\left(x^2 - \frac{1}{2}x^2\right) - 3x + 4 > 0$$
$$\frac{1}{2}x^2 - 3x + 4 > 0$$
4. **Multiply both sides by 2 to clear the fraction:**
$$2 \times \left(\frac{1}{2}x^2 - 3x + 4\right) > 2 \times 0$$
$$\cancel{2} \times \frac{1}{\cancel{2}} x^2 - 6x + 8 > 0$$
$$x^2 - 6x + 8 > 0$$
5. **Factor the quadratic:**
$$x^2 - 6x + 8 = (x - 2)(x - 4)$$
6. **Analyze the inequality:**
We want to find where
$$(x - 2)(x - 4) > 0$$
7. **Determine intervals:**
- The roots are $x=2$ and $x=4$.
- The quadratic opens upwards (coefficient of $x^2$ is positive).
8. **Sign analysis:**
- For $x < 2$, both $(x - 2)$ and $(x - 4)$ are negative, so their product is positive.
- For $2 < x < 4$, one factor is positive and the other negative, so product is negative.
- For $x > 4$, both factors are positive, so product is positive.
9. **Solution:**
$$x < 2 \quad \text{or} \quad x > 4$$
**Final answer:**
$$\boxed{x < 2 \text{ or } x > 4}$$
Quadratic Inequality B19241
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.