Plugging in $x = -\frac{2}{3}$ into the function $x^3 - 4x^2 + 4x + 9$ gives approximately 4.26, and plugging in $x = 2$ gives 9.

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Here are five related questions:

1. What is the derivative of the function $x^3 - 4x^2 + 4x + 9$?
2. How do you find the critical points of this function?
3. What is the behavior of the function as $x \to \infty$ and $x \to -\infty$?
4. How would you calculate the integral of this function over a specific interval?
5. How do you determine if the function has any inflection points?

Tip: When evaluating a polynomial at various points, always check if factoring the polynomial simplifies the process.