1. How a smooth smile curve is generated from 5 smile points : 10D RR, 25D RR, 10D SM, 25D SM and ATM? What are the commonly used extrapolation and interpolation techniques?
  2. I have seen people extrapolate smile curve beyond 5D points by assuming that the curvature (SM) stays the same and only skew(RR) changes. How fair is this assumption?