Question

I have to create the sin function from scratch in my Comp Sci class, and I am getting close to a solution. However, I am still having a few problems. If I put in a value of .5PI or less it works, but otherwise I get the incorrect result. Here is the code I have so far:

double i=1; double sinSoFar = 0; int term = 1; while(i >= .000001) {     i = pow(-1, term + 1) * pow(sinOf, 2*term-1) / factorial(2*term-1);     sinSoFar=sinSoFar + i;     term++; } 

Answer 1

Like Federico pointed, the problem probably is in your factorial() or pow(). I ran a test that worked fine replacing your functions with the pow() function provided in the Math class, and this factorial():

public static long factorial(long n) {         if      (n <  0) throw new RuntimeException('Underflow error in factorial');         else if (n > 20) throw new RuntimeException('Overflow error in factorial');         else if (n == 0) return 1;         else             return n * factorial(n-1); }