X = (0, -1)
Y = (11, -1)
Z = (0, 6)
A = (0.7692266666666673, 0.9005600000000008)
B = (2.052057142857144, 3.717209523809525)
C = (4.561942857142858, 5.669342857142859)
D = (7.350704761904764, 5.33469142857143)
E = (9.079737142857145, 3.5777714285714297)
F = (9.972140952380954, 1.597750476190477)
f = Polynomial({A, B, C, D, E, F})
a = Integral(f, 0.5, 10.5)