(t2+1)22t3
a(t2+1)2t3
a(t2+2)2t3
a(t2+1)22t3
Tangent at P: ty = x + at^2 or y = x/t + atNormal at S: y + xt = 2at + at^3Solving, 2y = at + 2at + at^3y = a(t^2 + 1) / 2t^3