t = -1.8 (slider from -10 to 10, step 0.1)
a(t) = ((-(t - 5))) / 3
b(t) = t
P: (a(t), b(t))
c(t) = sqrt(t)
d(t) = t
Q: (c(t), d(t))
gl1: y^(2) - x = 0
e(t) = t^(2)
R: (e(t), d(t))