C :

# include <stdio.h>
# include <math.h>
# define PI 3.141592658979

int main()
{
    double a, x, y;
    scanf("%lf", &a);
    x = (a / 180) * PI;
    y = fabs(sin(x * x)) / (1 - cos(x));
    printf("%lf", y);
    return 0;
}

C++ :

#include<iostream>
using namespace std;
#include<cmath>
int main()
{
	const double PI=3.14159265358979;
	double x,y;
	cin>>x;
	x=x*PI/180;
	y=abs(sin(x*x))/(1-cos(x));
	cout<<y;
	return 0;
}