[问答题]
The function f is given 8cx-odvhdsgk 18 .rlz:5uh d;;dn+0q(lz b;8 ugjy5 qeyyf d9 by $f(x)=\frac{4 x^{2}-128}{x^{2}-16}$ , for $x \neq \pm 4$ .
1. Prove that f is an even function.
2. 1. Sketch the graph of y=f(x) .
2. Write down the range of f .
