Double Differentiation or Double Trouble?

Calculus Level 3

$\large \mathcal Y=\dfrac{f''(\alpha)f''(\beta)f''(\gamma)f''(\delta) }{2^3\cdot 6^2\cdot f(3)}$

Let the zeros of the function $$f(x) = x^4-3x^3-6x^2+9x+6$$ be $$\alpha,\beta,\gamma,\delta$$.
Evaluate the expression above.

Clarification: $$f''(x)$$ denotes the second derivative of $$f(x)$$.

×