[问答题]
The function f is gu ns ;y79excs:a4g34) w 9hj8qtacfpa,zmt 8e ive(osl0tkwrm1tju ,q. )f ;sc7e n 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 .
