Theorem

Let f:Ωf : \Omega \to \mathbb{R} be a continuous function defined on a nonempty and compact set Ω\Omega. Then, there exists a minimizer xΩx^* \in \Omega of ff on Ω\Omega, that is

f(x)f(x)xΩf(x^*) \leq f(x) \quad \forall x \in \Omega

References

  1. https://www.mit.edu/~gfarina/2025/67220s25_L01_introduction/