CHALLITA - TABCHOURI

f(x) = x^(2)
m = -2.2 (slider from -10 to 10, step 0.0010)
M: (m, f(m))
a = Tangent(M, f(x))
b = OrthogonalLine(M, a)
A = Intersect(a, yAxis)
B = Intersect(b, yAxis)
C = Midpoint(B, A)
α = Angle(A, M, B)