Let
be a continuous function defined over a real interval. The function has at points x 1 , x 2 ∈ I {\displaystyle {}x_{1},x_{2}\in I} , x 1 < x 2 {\displaystyle {}x_{1}<x_{2}} , local maxima. Prove that the function has between x 1 {\displaystyle {}x_{1}} and x 2 {\displaystyle {}x_{2}} has at least one local minimum.