Quadratic Formula C03745
1. The problem is to solve the quadratic equation $$7x^2 + 2x + 8 = 0$$ using the quadratic formula.
2. The quadratic formula is given by:
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $a$, $b$, and $c$ are coefficients from the quadratic equation $ax^2 + bx + c = 0$.
3. Identify the coefficients:
- $a = 7$
- $b = 2$
- $c = 8$
4. Calculate the discriminant:
$$\Delta = b^2 - 4ac = 2^2 - 4 \times 7 \times 8 = 4 - 224 = -220$$
5. Since the discriminant is negative ($\Delta = -220$), the solutions are complex (no real roots).
6. Calculate the roots using the quadratic formula:
$$x = \frac{-2 \pm \sqrt{-220}}{2 \times 7} = \frac{-2 \pm \sqrt{220}i}{14}$$
7. Simplify $\sqrt{220}$:
$$\sqrt{220} = \sqrt{4 \times 55} = 2\sqrt{55}$$
8. Substitute back:
$$x = \frac{-2 \pm 2\sqrt{55}i}{14} = \frac{-2}{14} \pm \frac{2\sqrt{55}i}{14} = -\frac{1}{7} \pm \frac{\sqrt{55}}{7}i$$
Final answer:
$$x = -\frac{1}{7} \pm \frac{\sqrt{55}}{7}i$$