O = Intersect(zAxis, xAxis)
O' = (0, 0, 3)
a, c, d, b = Cylinder(O, O', 3)
z_1 = 2.15 (slider from 0.5 to 2.5, step 0.025)
e: z = z_1
f = IntersectPath(e, a)
texte1 = LaTeX(z_1, true, true)