Quadratic Formula C7Ef84
1. **State the problem:** Solve the quadratic equation $ax^2 + bx + c = 0$ using the quadratic formula.
2. **Formula:** The quadratic formula is given by
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
This formula finds the roots of any quadratic equation where $a \neq 0$.
3. **Example:** Solve $2x^2 - 4x - 6 = 0$.
4. **Identify coefficients:** Here, $a=2$, $b=-4$, and $c=-6$.
5. **Calculate the discriminant:**
$$\Delta = b^2 - 4ac = (-4)^2 - 4 \times 2 \times (-6) = 16 + 48 = 64$$
6. **Apply the quadratic formula:**
$$x = \frac{-(-4) \pm \sqrt{64}}{2 \times 2} = \frac{4 \pm 8}{4}$$
7. **Find the two roots:**
- For $+$ sign:
$$x = \frac{4 + 8}{4} = \frac{12}{4} = 3$$
- For $-$ sign:
$$x = \frac{4 - 8}{4} = \frac{-4}{4} = -1$$
8. **Answer:** The solutions to the equation $2x^2 - 4x - 6 = 0$ are $x=3$ and $x=-1$.
This method works for any quadratic equation by substituting the values of $a$, $b$, and $c$ into the formula and simplifying step-by-step.