1. **Stating the problem:** A quadratic equation is any equation that can be written in the form $$ax^2 + bx + c = 0$$ where $a$, $b$, and $c$ are constants and $a \neq 0$.
2. **Methods to solve quadratic equations:**
- **Factoring:** Express the quadratic as a product of two binomials, then set each equal to zero.
- **Quadratic formula:** Use $$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$ which works for all quadratics.
- **Completing the square:** Rewrite the equation to form a perfect square trinomial.
- **Graphing:** Find the points where the parabola crosses the x-axis.
3. **Step-by-step example using the quadratic formula:**
Given $$2x^2 - 4x - 6 = 0$$
- Identify coefficients: $a=2$, $b=-4$, $c=-6$.
- Calculate the discriminant: $$\Delta = b^2 - 4ac = (-4)^2 - 4 \times 2 \times (-6) = 16 + 48 = 64$$.
- Since $\Delta > 0$, there are two real solutions.
- Apply the formula:
$$x = \frac{-(-4) \pm \sqrt{64}}{2 \times 2} = \frac{4 \pm 8}{4}$$
- Calculate each root:
- $$x_1 = \frac{4 + 8}{4} = \frac{12}{4} = 3$$
- $$x_2 = \frac{4 - 8}{4} = \frac{-4}{4} = -1$$
4. **Common mistakes to avoid:**
- Forgetting to set the equation equal to zero before solving.
- Miscalculating the discriminant or forgetting the $\pm$ sign in the quadratic formula.
- Not simplifying the square root fully.
- Errors in factoring by missing factors or signs.
5. **Summary:** Choose the method based on the equation's form. Factoring is quickest if possible, otherwise use the quadratic formula for a guaranteed solution. Always check your solutions by plugging them back into the original equation.
Quadratic Solving D6Ed4F
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