Dears all,

I wonder why 243 is so different in my program output, following is my program:

```
bool isPowerOfThree(int n) {
double result = log(n)/log(3);
return result == (int)result;
}
```

The returned boolean is under expectation when n = 1,3,9,27,81 while failed in 243

Does anyone know the reason?? Thanks