fkampas
(Frank Kampas)
1
Minimize[{x^2 - y^2,
Cos[x - y] >= 1/2, -5 <= x <= 5, -5 <= y <= 5}, {x, y}] (* returns unevaluated *)
Minimize[{x^2 - y^2,
Reduce[{Cos[x - y] >= 1/2, -5 <= x <= 5, -5 <= y <= 5}, {x,
y}]}, {x, y}] (* returns *)
{1/9 (-150 \[Pi] + 25 \[Pi]^2), {x -> 5 - (5 \[Pi])/3, y -> 5}}
3 Likes
brucem
(Bruce Miller)
2
Useful technique.
Was there an implict question?
fkampas
(Frank Kampas)
3
No specific question, I thought people might find this interesting or useful.
Neat observation, Frank, +1 
Frank, you may want to take a look at the following discussion:
** An Example of the symbolic Nature in Mathematica’s Numeric Process **
which was inspired by the very code you posted here.