Quadratic Roots 33Cf07
1. **State the problem:** Determine the nature of the roots of the quadratic equation $x^2 + x - 1 = 0$.
2. **Recall the formula:** The discriminant $\Delta$ of a quadratic equation $ax^2 + bx + c = 0$ is given by:
$$\Delta = b^2 - 4ac$$
3. **Important rule:**
- If $\Delta > 0$, roots are real and distinct.
- If $\Delta = 0$, roots are real and equal.
- If $\Delta < 0$, roots are complex (not real).
4. **Calculate the discriminant:**
For $x^2 + x - 1 = 0$, $a=1$, $b=1$, $c=-1$.
$$\Delta = 1^2 - 4 \times 1 \times (-1) = 1 + 4 = 5$$
5. **Interpret the result:**
Since $\Delta = 5 > 0$, the roots are real and distinct.
6. **Check if roots are rational or irrational:**
Since $\Delta = 5$ is not a perfect square, roots are irrational.
**Final answer:** The roots of the quadratic equation $x^2 + x - 1 = 0$ are irrational and distinct.