10. Given the function
$$
f(x)=\log _{2}\left[a x^{2}+(a+2) x+(a+2)\right] \text {. }
$$

If $f(x)$ has a maximum or minimum value, then the range of values for $a$ is $\qquad$ .
10. $(-2,0) \cup\left(\frac{2}{3},+\infty\right)$.

Since $f(x)$ has a maximum or minimum value, $a$ satisfies $\left\{\begin{array}{l}a>0, \\ \Delta \geq 0 .\end{array}\right.$ Solving this, we get $-2 < a < 0$ or $a > \frac{2}{3}$.