[问答题]
The function f is d
ca (fch8d 7k4refined by
kai d g066cg wzv863pb22jpwlbh* vr, $f(x)=e^{2 x}-4 e^{x}+2$ , for $ x \in \mathbb{R}$, $x \leq a$ , where $a \in \mathbb{R}$ .
Part of the graph of y=f(x) is shown in the following diagram.
1. Find the largest value of a such that f has an inverse function.
2. For this value of a , find an expression for $ f^{-1}(x)$ , stating its domain.
