Is there a trick to linearise the product of two non-negative (decision) variables in linear optimisation?
Let $x_1$ and $x_2$ be these variables with $0 \leq x_1 \leq a$, $a \in \mathbb{R}_+$ and $b \leq x_2$, $b \in \mathbb{R}_+$.
I assume it is not possible because $x_2$ is not bounded above, but if I choose some large $M \in \mathbb{R}_+$ such that $b \leq x_2 \leq M$, then can the linearisation be done?
If not, what are good approximation techniques?
Thanks in advance!