2.30

#include<iostream>using namespace std;int sroot(int i) {return sqrt(i); } long sroot(long l) {return sqrt(l); } double sroot(double d) {return sqrt(d); } int main() {int i=16;long l=2500;double d=12.25;cout<<"i的二次方根:"<<sroot(i)<<endl;cout<<"l的二次方根:"<<sroot(l)<<endl;cout<<"d的二次方根:"<<sroot(d)<<endl;return 0; }