Why do i get this error???

For some reason i keep getting this error in the following code
error C2660: 'pow' : function does not take 1 parameters This error appears twice for the two lines that i am using pow can anyone please help me

#include <iostream.h>
#include <math.h>
void main()
{
double a,b,c;
double r1;
double r2;
cout<<"Please enter the a: ";
cin>>a;
cout<<"Please enter the b: ";
cin>>b;
cout<<"Please enter the c: ";
cin>>c;
r1 = (-1*b+pow((b*b-4*a*c)*0.5))/(2.0*a);
r2 = (-1*b-pow((b*b-4*a*c)*0.5))/(2.0*a);
if (r1>=0 && r2>=0)
{
cout<<"the roots are reals "<<endl;
}
else
{
cout<<"the roots are not real"<<endl;

}
if (r1 > r2)
{
cout<<"the largest root is "<<r1<<endl;
}
else
{
cout<<"the largest root is "<<r2<<endl;
}
}

Code:

---

double r;
r = pow(13, 3);
// thirteen to the third power

---

pow(double arg1, double arg2)

Seems like you've lost track of your own code (is it?).

Bad thing if that happens...
But for once MSVC++ gives an error message that is actually comprehensible :D