I cannot figure out what I did wrong with this code to calculate cos(x), the function for the program is attached!

package cosx;

import java.util.Scanner;

public class cosx {

public static void main(String[] args) {

Scanner input = new Scanner(System.in);

System.out.print("Enter amount in degrees: ");

double degrees = input.nextDouble();

System.out.print("Enter the number of series: ");

int n = input.nextInt();

System.out.println(getCos(degrees, n));

System.out.println(Math.cos(convertToRadians(degre es)));

}

public static double getCos(double degrees, int n) {

double cos = 0;

double numerator = 0;

int denominator = 0;

for (int i = 0; i <= n; i++, i++) {

numerator = getNumerator(Math.pow(-1, i));

denominator = getFactorial(2 * i);

cos += numerator / denominator;

}

return cos;

}

public static double convertToRadians(double degrees) {

return degrees * Math.PI / 180;

}

public static int getFactorial(int n) {

int factorial = 1;

for (int i = 1; i <= n; i++) {

factorial *= i;

}

return factorial;

}

public static double getNumerator(double degrees, int n) {

return convertToRadians(degrees) * Math.pow(-1, n);

}

}