Could anyone help me with this quest?Find the minimum-weight truss for the following condition. The load on the truss is
30,000 lb., directed downward. The allowable yield stress is 8,000 psi. Stress in the truss
must also be less than the critical buckling stress divided by a safety factor of 1.2.
sigma = pi^(2)EI/(L^(2)*A)
where E = 30,000,000 psi. The cross-sectional area of each member is circular,
A = π ⋅r^2 and I = π ⋅r^(4)/(4)
L is the length of each member and r is its radius.
(a) Formulate this problem as a mathematical program.
(c) Derive KKT conditions for the problem.

Question

Could anyone help me with this quest?Find the minimum-weight truss for the following condition. The load on the truss is 
30,000 lb., directed downward. The allowable yield stress is 8,000 psi. Stress in the truss 
must also be less than the critical buckling stress divided by a safety factor of 1.2.
sigma = pi^(2)EI/(L^(2)*A)
where E = 30,000,000 psi. The cross-sectional area of each member is circular, 
A = π ⋅r^2 and I = π ⋅r^(4)/(4) 
 L is the length of each member and r is its radius.
(a) Formulate this problem as a mathematical program. 
(c) Derive KKT conditions for the problem.