Quadratic Roots 199C27
1. **State the problem:** Solve the quadratic equation $$3x^2 + 5x - 2 = 0$$ to find the roots (values of $x$).
2. **Formula used:** For a quadratic equation $$ax^2 + bx + c = 0$$, the roots are given by the quadratic formula:
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
3. **Identify coefficients:** Here, $a = 3$, $b = 5$, and $c = -2$.
4. **Calculate the discriminant:**
$$\Delta = b^2 - 4ac = 5^2 - 4 \times 3 \times (-2) = 25 + 24 = 49$$
5. **Evaluate the roots:**
$$x = \frac{-5 \pm \sqrt{49}}{2 \times 3} = \frac{-5 \pm 7}{6}$$
6. **Find each root:**
- For the plus sign:
$$x = \frac{-5 + 7}{6} = \frac{2}{6} = \frac{1}{3}$$
- For the minus sign:
$$x = \frac{-5 - 7}{6} = \frac{-12}{6} = -2$$
7. **Final answer:** The roots are $$\left\{-2, \frac{1}{3}\right\}$$ which corresponds to option A.
This means the parabola crosses the x-axis at $x = -2$ and $x = \frac{1}{3}$.