' - - File: XII_Contour9b.txt

' Given (x,y) --> <F, H>, construct the directed field + Contour overlay.

F{x,y} =y
H{x,y} = Cos[x]

M{x,y} = -F{x,y} / H{x,y}

r = 3
a = -3  :  b = 3  :  n = 15
c = -3  :  d = 3  :  m = 15

'PlotDirField[F, H, {a,b,n}{c,d,m}]

PlotSlopeField[M,{-r,r,15}{-r,r,15}]

'PlotContour1[M,{-r,r,-r,r}{2,2}{-6,6,.5}]
PlotContour1[M,{-r,r,-r,r}{2,-2}{-6,6,.5}]



