Just really need to confirm that. Otherwise, even if I have perfect codes, with no REAL solution i still cant test it.
My other classmates are giving me weird numbers.

Some suggestions. Your integrand function can be shortened.

Code (Text):

double integrand(double x)
{
return sin(x);
}

Also, you could write a function that does essentially what you do in main. It should take three parameters: left endpoint, right endpoint, number of subintervals, and should return the computed value for that interval. The 10-element array would still be in main -- just loop through each element in the array and call your calculating function for each of the intervals 0 - 1, 1 - 2, ... 9 -10.