If I define these variables:

```
double x0, xn, h;
int n;

```

and I have this mathematical expression:

```
h = (xn - x0)/n;

```

Is it necessary that I cast n into double prior doing the division for maximum accuracy like in

```
h = (xn - x0)/ (double) n;

```

I wrote a program to check the above but both expressions give the same answers. I understand that C will promote the integer to double type as variables xn and x0 are of type double but strangely enough in a book, the second expression with casting was emphasized. 

My question would be if I'm thinking right.

Thanks a lot...