approxmation de la fonction sinus

public static float appr_sin(float x, int n){
	float X = x;
	int p=1;
	for(int i=1;i<=2*n+1;i+=2){
		res += p*X/factoriel( i ); p*=-1; X *= X*X;
	}
	return res;
}

public static int factoriel(int n){
	if( n==0 )
		return 1;
	return factoriel(n-1)*n;
}