(4) Consider the point y = (1/2, 0, 0) ∈ Ω. Is y an interior point of Ω? Characterize all the feasible directions e = (e1, e2, e3) ∈ R at y (a picture could help). Is y a (strict) local maximizer of f? (5) Consider the point z = (1/2, 1/2, 1/2) ∈ Ω. Is z an interior point of Ω? Characterize all the feasible directions e = (e1, e2, e3) ∈ R at z. Is z a (strict) local maximizer of f? What is the ...