' - - File: XII_Contour7d.txt
' - - Slope (without (0,rt) particular solution) +  directed Field +  Contour study.

H{x,y} = -x^3 /3 + x - y^2
M{x,y} = -Diff[H,x] / Diff[H,y]

Fx{x,y} = Diff[H,x]  :  Fy{x,y} = Diff[H,y]
r =5 :  er = 0.2  :  sg = .3 : rt = Sqrt[10]

PlotDirField[Fx,Fy,{-r,r,20}{-r,r,20}]

PlotSlopeField[M,{-r,r,20}{-r,r,20}]      ' Remove particular solution.

' Adjust screen for size, any arrows, etc. FIRST. Then remove comment below. (Save time.)

PlotContour[H,{-r,r,-r,r}{3,3}{-10,-10,1}{er,sg}]

' ( ***Be sure to enter Enter Key if no CR is present.from prevous work.***)




