$$\begin{aligned} &\begin{aligned} & \lim _{x \rightarrow 0}(f(2+x))^{3 / x}=\left(1^{\infty} \text { form }\right) \\ & e^{\lim _{x \rightarrow 0 x}^3(f(2+x)-1)}=e^{\lim _{x \rightarrow} 3 f^{\prime}(2+x)} \\ & =e^{3 f^{\prime}(2)} \\ & =e^{12} \\ & \Rightarrow \alpha=12 \\ & y=4 x^3-4 x^2-4(12-7) x-12 \\ & y=4 x^3-4 x^2-20 x-12 \\ & y=4\left(x^3-x^2-5 x-3\right) \\ & =4(x+1)^2(x-3) \end{aligned}\\ &\text { It meets the } x \text {-axis at two points } \end{aligned}$$