We now have market data for delta = 0.1, 0.25, 0.5, 0.75, 0.9.I have two questions:1. How do you guys extrapolate between 0 and 0.1, and between 0.9 and 1?2. Do you find implied vol by iteration (start with, say ATM vol, find the delta, the vol, and carry on until the two vols are the same?)