The equation of normal at (at,at) to the hyperbola xy=a2 is
Equation of tangent is s1=0 normal is ⊥ to tangent and passing through
(at,at) is xt3−yt−at4+a=0
The equation of normal to a hyperbola x2a2−y2b2=1 at a point with parameter θ is
axcosθ−bycotθ=a2+b2