C++ tan() Function

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
    double x, y;

    cout << "Enter Angle : ";
    cin >> x;
    cout << endl;

    y = tan(x * (M_PI/180));

    cout << "Trigonometric Ratio : " << y << endl;

    return 0;
}