[问答题]
The function f is d
whz m4/o q,grfwak8*(: *y1o5hnx eqa-ji qf/cej;zu(a4loqk;z- y(efined by $f(x)=e^{2 x}-4 e^{x}+2$ , 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.
