1. The problem statement, all variables and given/known data The question is asking us to minimize the maximum bending moment by changing l3. l1=3(m) l2=6.5(m) l4=12(m) P1=1200(KN) P2=2300(KN) P3=410(KN) and we know that obviously, 6.5<l3<12 2. Relevant equations 3. The attempt at a solution We made relevant cuts and acquired the equations for our bending moments in different sections of the beam.In the end,we have too many unknowns and not enough equations.We even tried plotting 3D graphs on MATLAB to find the optimum point,however we failed since we still had too many unknowns.We tried trial and error to give different values and we optimized it at l3=6.5(m),but we can't really get the value using maths.Something doesn't feel right about our method.