4．设 $f(x)=\left\{\begin{array}{c}1-\sqrt{x}, x \geq 0 \\ 2^{x}, x<0\end{array}\right.$，则 $f(f(-2))=$
参考答案$C$
2015 高考数学第 4 题答案解析
2015_退役省自主命题 (2015·文)
2015_退役省自主命题 (2015·文)
4．设 $f(x)=\left\{\begin{array}{c}1-\sqrt{x}, x \geq 0 \\ 2^{x}, x<0\end{array}\right.$，则 $f(f(-2))=$