Consider the problem of minimizing
f(x1,x2)=(x1 - x2)^3 + (x1 - x2)^2 + (x2 - 1)^2
over â„^2.
(b) Find all the local minimum points of f over â„^2.
(c) Does f have any global minimum point over â„^2? Justify your answer.
(d) Find two real numbers a1 and a2 such that f is a convex function over the convex set S={(x1,x2)∈â„^2:a1x1+a2x2<1}.