118 Classical Optimization Techniques
subject to
x 22 −x 1 ≥ 0
x 12 −x 2 ≥ 0
−^12 ≤x 1 ≤^12 , x 2 ≤ 1X 1 ={
0
0}
, X 2 ={
0
− 1}
, X 3 ={
−^12
1
4}2.76 Consider the following optimization problem:Minimizef= −x 12 −x^22 +x 1 x 2 + 7 x 1 + 4 x 2subject to
2 x 1 + 3 x 2 ≤ 24
− 5 x 1 + 12 x 2 ≤ 24
x 1 ≥ 0 , x 2 ≥ 0 , x 2 ≤ 4Find a usable feasible direction at each of the following design vectors:X 1 ={
1
1}
, X 2 ={
6
4}