f(x) = sin(x)
g(x) = cos(2 * x)
h(x) = g(x) - f(x)
A = Root(h, 0.7853981633974483)
B = Root(h, 0.7853981633974483, 6.283185307179586)
C, D, E = Intersect(f, g, 0.7853981633974483, 9.42477796076938)
F = Intersect(f, g, 0, 1.5708)
G = Intersect(f, g, (-1.5707963267948966, -1))