1. Let's start by stating the problem: We want to find the sum and product of the roots of a quadratic equation and express the roots \(\alpha\) and \(\beta\) as the subject.
2. Consider the general quadratic equation:
$$ax^2 + bx + c = 0$$
where \(a \neq 0\).
3. The roots of this quadratic equation are \(\alpha\) and \(\beta\).
4. According to Vieta's formulas, the sum and product of the roots are given by:
- Sum of roots: $$\alpha + \beta = -\frac{b}{a}$$
- Product of roots: $$\alpha \beta = \frac{c}{a}$$
5. To make \(\alpha\) and \(\beta\) the subject, we use the fact that they satisfy the quadratic equation:
$$x^2 - (\alpha + \beta)x + \alpha \beta = 0$$
Substituting the sum and product, we get:
$$x^2 - \left(-\frac{b}{a}\right)x + \frac{c}{a} = 0$$
which simplifies to:
$$x^2 + \frac{b}{a}x + \frac{c}{a} = 0$$
6. Solving for \(x\) (which represents \(\alpha\) or \(\beta\)) using the quadratic formula:
$$x = \frac{-\frac{b}{a} \pm \sqrt{\left(\frac{b}{a}\right)^2 - 4 \cdot 1 \cdot \frac{c}{a}}}{2}$$
7. Simplify the expression:
$$x = \frac{-\frac{b}{a} \pm \sqrt{\frac{b^2}{a^2} - \frac{4c}{a}}}{2} = \frac{-\frac{b}{a} \pm \frac{\sqrt{b^2 - 4ac}}{a}}{2}$$
8. Multiply numerator and denominator by \(a\) to clear denominators:
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
9. Therefore, the roots \(\alpha\) and \(\beta\) are:
$$\alpha, \beta = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
This shows how to find the sum and product of roots and express the roots themselves as the subject of the quadratic equation.
Sum Product Roots 2D0Cdc
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