f(x) = 1 / 4 x^(2)
g(x) = 4
a = Integral(f, g, -4, 4)
x1 = Point(xAxis)
x2 = Point(xAxis)
S1 = Intersect(f, g, 1)
S2 = Intersect(f, g, 2)
A = (-4, 0)
b = Segment(S1, x1)
c = Segment(S2, x2)