am trying to write a program which compute sin using an a equation instead of the function of sin in cmath libry.

"the equation is like this Tn = (Tn-2 *(-1) *x*x)/ n*(n-1)

```
#include<iostream>
#include<cmath>
using namespace std;
int main()
{
int factorial(int);
int n =1, i = 1;
double sum, t, x;
char choice;
//r = x * (PI / 180)
cout<<"Please enter an angle value => ";
cin>>x;
cout<<"Is the angle value in Degree or Radian?"<<endl;
cout<<"Type D if its in degree "<<endl;
cout<<"Type R if its in radian "<<endl;
cin>>choice;
if((choice == 'R') || (choice == 'r'))
{
do
{
t = sum; i++; n++;
sum = n-2*(-1) * pow(x,2)/ (n * (n-1));
}
while(abs(sum>0.00001));
cout<<"what"<<endl;
}
else
{
cout<<"eror\n";
}
return 0;
}
```