What will be the output of the following program?

#include<iostream.h>
double AptitudeFunction(double, double, double = 0, double = 0, double = 0);
int main()
{
    double d = 2.3;
    cout<< AptitudeFunction(d, 7) << ' ';
    cout<< AptitudeFunction(d, 7, 6) << endl;
    return 0; 
}
double AptitudeFunction(double x, double p, double q, double r, double s)
{
    return p +(q +(r + s * x)* x) * x;
}