int factorial(int n)
{
	int fact=1;
	while(n>0)
	{
		fact=fact*(n);
		n=n-1;
	}
	return fact;
}



int ordered_subsets(int n, int k)
{
	int pnum;
	pnum=factorial(n)/factorial(n-k);
	return pnum;
}


int binomial(int n, int k)
{
	int cnum;
	cnum=ordered_subsets(n,k)/factorial(k);
	return cnum;
}


double cosine(double x, int n)
{
	double num=1;
	int a=2;
	int c=-1;
	while(a<=n)
	{
		num+=(c*pow(x,a))/factorial(a);
		c=c*(-1);
		a=a+2; 
	}
	return num;
}