The purpose of this exercise is to provide practice using LINGO or Excel Solver. Find the values of X and Y that minimize the function
Min X2 - 4X + Y2 + 8Y + 20
Do not assume non-negativity of the X and Y variables. Recall that by default LINGO assumes nonnegative variables. In order to allow the variables to take on negative values, you can add
@FREE(X); @FREE(Y);
Alternatively, if you want LINGO to allow for negative values by default, in the LINGO menu select Options and then click General Solver, and then uncheck the Variables assumed nonnegative tab?