Let any point on x24+y21=1 be (2cosθ,sinθ).
tangent at that point is xcosθ2+ysinθ=1 …(1)
Let point of intersection of tangents at P
and Q be R(h,k)
Chord of contact for E2:hx6+ky3=1 …(2)
(1) and (2) are indentical
⇒cosθ2⋅h6=sinθk3=1
cosθ=h3,sinθ=k3
⇒h2+k2=9
x2+y2=6+3
Clearly, locus of point of intersection of tangents lie on director circle of E2
∴ Angle between tangents =π2
∴n2=22=4