Thread: Sine function, can't get factorial to work

I've been having issues with trying to get this program to work. The program's purpose is to compute the sine function without using the Math.sin(). At first I had trouble with the for loop but I finally understood how it worked, so it's not much of an issue anymore. My next problem is trying to get this factorial to work. I've look at tutorials and I think I'm doing the right thing but when I compile I get several errors (stated in code).

Original Code

/* This program is suppose to compute the Sine function without using Math.sin */
 
import java.io.*;
public class x
{
public static void main(String args[]) throws IOException
{
 
BufferedReader keybd = new BufferedReader(new InputStreamReader(System.in));
 
double Rad, Sine;
int MaxE;
Sine = 0.0;
 
System.out.println("Enter Radians: ");
Rad = Double.parseDouble(keybd.readLine());
 
for (int a = 1; a <= 11; a++)
{
Sine += Math.pow(-1,a)*Math.pow(Rad,2*a+1)/factorial(2*a+1);
}
 
System.out.println("The value of Sine is " + Sine);
 
}
 
}

Errors

x.java:20: cannot find symbol
symbol  : method factorial(int)
location: class x
Sine += Math.pow(-1,a)*Math.pow(Rad,2*a+1)/factorial(2*a+1);
                                           ^
1 error

I think I'm on the right track but I'm not sure how to troubleshoot these errors yet since I'm still pretty new. Any help is appreciated!

Hello Actinistia.

The issue is that factorial(2 * a + 1) is seen as a method and obviousally there isn't this method within your code.
factorial isn't even a variable within your code so what are you attempting to do here please?

Originally Posted by erdy_rezki

just this

What is that? And why resurrect a year old post, especially when the contribution is gibberish.