Using Mathematica to solve ODEs

yplus@x_, yplus0_D := x + Sqrt@2 Hx^2-xL + yplus0^2D; yminus@x_, yminus0_D := x-Sqrt@2 Hx^2-xL + yminus0^2D Plot@8yplus@x, 10D, yminus@x, -10D ................
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