c++一道基础题

#include<iostream>
#include<cmath>
int main()
{double x;
cout<<"please input x";
cin>>x;
cout<<"y="<<sqrt(pow(sin(x),2.5));
return 1;}

哪错了

#include<iostream>
#include<cmath>
using namespace std; //缺少命名空间.

int main()
{
double x;
cout<<"please input x";
cin>>x;
cout<<"y="<<sqrt(pow(sin(x),2.5));
return 1;
}