var('x')
d2 = 2.265
d12 = d2 + 0.5
beta = 0.85
du = 3.015
@interact
def _(u=(0.001, 2, 0.1)):
f = -(exp(beta*u)*(-x^2/4 + d12^2) + (1 - exp(beta*u))*(-((x^2 + du^2 - d12^2)/(2*x))^2 + du^2))
g = -(1 - exp(beta*u))*(-((x^2 + du^2 - d12^2)/(2*x))^2 + du^2)
h = 0
dot = point((2*d12,f(2*d12)),pointsize=10,rgbcolor=(0,0,0))
dot2 = point((du + d12, g(du + d12)),pointsize=10,rgbcolor=(0,0,0))
pt = plot(f, (d2*2, d12*2), color='green', thickness=1)
pt2 = plot(g, (d12*2, d12 + du), color='red', thickness=1)
pt3 = plot(h, (d12 + du, 2*du), color='blue', thickness=1)
show(pt + pt2 + pt3 + dot + dot2)
