Calculating sin, cos with Taylor Series

#include <iostream>
#include <stdlib.h>
#include <math.h>

using namespace std;
// Factorial Function
int factorial(int n){
    if(n == 0){
        return 1;
    }
    else{
        return n * factorial(n-1);
    }
}

// Sinus Function
double sinTaylor(double angle){
    double rads = angle * M_PI / 180;
    double sum = 0;
    int sign = 1;
    for(int i=1; i<=33; i+=2){
        sum += sign * pow(rads, i) / factorial(i);
        sign = -sign;
    }
    return sum;
}

// Cosinus Function
double cosTaylor(double angle){
    double rads = angle * M_PI / 180;
    double sum = 0;
    int sign = 1;
    for(int i=0; i<=32; i+=2){
        sum += sign * pow(rads, i) / factorial(i);
        sign = -sign;
    }
    return sum;
}

int main()
{
    cout << "sin(0) = " << sin(0) << " = " << sinTaylor(0) << endl;
    cout << "sin(15) = " << sin(15* M_PI / 180) << " = " << sinTaylor(15) << endl;
    cout << "sin(30) = " << sin(30* M_PI / 180) << " = " << sinTaylor(30) << endl;
    cout << "sin(45) = " << sin(45* M_PI / 180) << " = " << sinTaylor(45) << endl;
    cout << "sin(60) = " << sin(60* M_PI / 180) << " = " << sinTaylor(60) << endl;
    cout << "sin(75) = " << sin(75* M_PI / 180) << " = " << sinTaylor(75) << endl;
    cout << "sin(90) = " << sin(90* M_PI / 180) << " = " << sinTaylor(90) << endl;
    cout << endl;
    cout << "cos(0) = " << cos(0) << " = " << cosTaylor(0) << endl;
    cout << "cos(15) = " << cos(15* M_PI / 180) << " = " << cosTaylor(15) << endl;
    cout << "cos(30) = " << cos(30* M_PI / 180) << " = " << cosTaylor(30) << endl;
    cout << "cos(45) = " << cos(45* M_PI / 180) << " = " << cosTaylor(45) << endl;
    cout << "cos(60) = " << cos(60* M_PI / 180) << " = " << cosTaylor(60) << endl;
    cout << "cos(75) = " << cos(75* M_PI / 180) << " = " << cosTaylor(75) << endl;
    cout << "cos(90) = " << cos(90* M_PI / 180) << " = " << cosTaylor(90) << endl;
    cout << endl;
    return 0;
}