Introduction to Group Theory - Exercises No. 6

<< Graphics`Graphics`

1. No crossing rule

H11 = 1; H22 = 2; H12 = 0.5;

DisplayTogether[
        Plot[H22 - (H12^2 + 2  V H12 + V^2)/(H11 - H22), {V, -8, 
            5}], Plot[
          H11 + (H12^2 + 2  V H12 + V^2)/(H11 - H22), {V, -8, 
            5}], ImageSize -> 550, 
        AxesLabel -> {"V", "E"}];