SetDirectory["C:\\Documents and Settings\\alpha\\My Documents\\Teaching\\Calculus II\\Homework"]

family1[x_,y_,c_]=y^2/2==Log[Abs[x]]+x+c
ContourPlot[Evaluate[{family1[x,y,-3],family1[x,y,-1],family1[x,y,0],family1[x,y,1],family1[x,y,2],family1[x,y,3]}],{x,-5,5},{y,-5,5},AxesLabel->{"x","y"},PlotPoints->100]

Export["figC9S3a.jpg",%,"JPEG"]

fam1[x_,c_]=Sin[x]+c
plot1=Plot[{fam1[x,-1],fam1[x,0],fam1[x,1]},{x,-5,5},PlotRange->{{-5,5},{-5,5}},PlotStyle->Blue];
fam2[x_,k_]=-Log[Abs[Sec[x]+Tan[x]]]+k
plot2=Plot[{fam2[x,-1],fam2[x,0],fam2[x,1]},{x,-5,5},PlotRange->{{-5,5},{-5,5}},PlotStyle->Red];
Show[plot1,plot2,AxesLabel->{"x","y"},AspectRatio->1]

Export["figC9S3b.jpg",%,"JPEG"]