D01RK_P0W_F C++ Header Example Program Results lower limit of integration (a) = 0 upper limit of integration (b) = 6.28319 choice of Gaussian rule (key) = 6 absolute accuracy requested = 0 relative accuracy requested = 0.0001 maximum number of subintervals = 20 approximation to the integral : -2.0967e-01 estimate of the absolute error : 4.4770e-14 number of function evaluations : 4