Answer 1

all you have to use is to include a cmath header file on the start of your program..and then use the sin and cos function.The usage is illustrated below:
#include<iostream>
#include<cmath>
using namespace std;
int main( )
{
float a;
cin>>a;//the value is taken as input
float sivalue, cosvalue;
sivalue= sin(a);
cosvalue= cos(a);
cout<<"the sine value is :"<<sivalue<<" and the cos value is : "<<cosvalue;
return 0;
}