∫ 1/sqrt(x) from 0 to 1 : OPEN4 Q = 1.99952 exact = 2 calls = 400 estimated error = 0.00299952 actual error = 0.000483882 ∫ 1/sqrt(x) from 0 to 1 : CLENSHAW_CURTIS Q = 1.99987 exact = 2 calls = 8 estimated error = 0.00299987 actual error = 0.000129682 ∫ log(x)/sqrt(x) from 0 to 1 : OPEN4 Q = -3.99926 exact = -4 calls = 424 estimated error = 0.00499926 actual error = 0.000739677 ∫ log(x)/sqrt(x) from 0 to 1 : CLENSHAW_CURTIS Q = -3.99486 exact = -4 calls = 36 estimated error = 0.00499486 actual error = 0.00514201 ∫ 4*sqrt(1-x*x)/M_PI from 0 to 1 : OPEN4 Q = 1.00000000000188915550 exact = 1.00000000000000000000 calls = 3924 estimated error = 2e-09 actual error = 1.88916e-12 ∫ 4*sqrt(1-x*x)/M_PI from 0 to 1 : CLENSHAW_CURTIS Q = 0.99999999999998023803 exact = 1.00000000000000000000 calls = 3756 estimated error = 2e-09 actual error = 1.9762e-14