Root System
1. We are given a cubic equation $$x^3 + ax^2 + bx + c = 0$$ with roots $$\alpha, \beta, \gamma$$ and the system:
$$\alpha u + \beta v + \gamma w = 0,$$
$$\beta u + \gamma v + \alpha w = 0,$$
$$\gamma u + \alpha v + \beta w = 0$$
which has a non-trivial solution $$(u, v, w) \neq (0,0,0)$$. We need to find the value of $$\frac{a^2}{b}$$.
2. The system matrix is:
$$\begin{pmatrix}
\alpha & \beta & \gamma \\
\beta & \gamma & \alpha \\
\gamma & \alpha & \beta
\end{pmatrix}$$
Non-trivial solutions exist if and only if the determinant of this matrix is zero.
3. Denote the matrix as $$M$$, then $$\det(M) = 0$$.
4. By calculating or using symmetry properties, we find:
$$\det(M) = (\alpha + \beta + \gamma)(\alpha^2 + \beta^2 + \gamma^2 - \alpha\beta - \beta\gamma - \gamma\alpha)$$
5. Since $$\alpha, \beta, \gamma$$ are roots of $$x^3 + ax^2 + bx + c = 0$$:
- $$\alpha + \beta + \gamma = -a$$
- $$\alpha\beta + \beta\gamma + \gamma\alpha = b$$
- $$\alpha \beta \gamma = -c$$
6. Substitute:
$$\det(M) = (-a)(\alpha^2 + \beta^2 + \gamma^2 - b) = 0$$
7. Use the identity:
$$\alpha^2 + \beta^2 + \gamma^2 = (\alpha + \beta + \gamma)^2 - 2(\alpha\beta + \beta\gamma + \gamma\alpha) = (-a)^2 - 2b = a^2 - 2b$$
8. Substitute back:
$$-a (a^2 - 2b - b) = -a(a^2 - 3b)=0$$
9. For non-trivial solution, either:
- $$a=0$$ (contradicts condition $$a \neq 0$$)
- OR $$a^2 - 3b=0 \Rightarrow a^2 = 3b$$
10. Therefore:
$$\frac{a^2}{b} = 3$$
Final answer: 3