Economics and non-linear regression model

1. (a) Consider a non-linear regression model y =0 + x1 + x 22 + u = (x) + u (1) where y is a dependent variable, x is a scalar independent (explanatory) variable, and u is an error such that E(u j x) = 0 and V(u j x) = 2 : Write the OLS and MM procedures (you may...