quiz problem

Show[Plot3D[Cos[x+y]*Sin[x-y],{x,0,2Pi},{y,0,2Pi},AxesLabel->{x,y,z},ViewPoint->{1,1,1}],Plot3D[y-Pi/2+1/2,{x,0,2Pi},{y,0,2Pi},AxesLabel->{x,y,z},ViewPoint->{1,1,1}]]

Show[Plot3D[Cos[x+y]*Sin[x-y],{x,0,2Pi},{y,0,2Pi},AxesLabel->{x,y,z},ViewPoint->{1,1,1}],ContourPlot3D[y-Pi==(3/2)*(x-Pi/2),{x,0,2Pi},{y,0,2Pi},{z,-1,1},AxesLabel->{x,y,z},ViewPoint->{1,1,1}]]

Show[Plot3D[Cos[Pi*(x^3*y^3+x^2*y+x*y^2)]*Sin[Pi*(x^3*y^3-x^2*y-x*y^2)],{x,1.9,2.1},{y,.9,1.1},AxesLabel->{x,y,z},ViewPoint->{1,1,1}],ContourPlot3D[y==1,{x,1.9,2.1},{y,.9,1.1},{z,-1,1}]]

14.6 #23

Plot3D[Sin[x*y],{x,0,2},{y,-1,1},AxesLabel->{x,y,z},ViewPoint->{1,1,1}]

ContourPlot[Sin[x*y],{x,0,2},{y,-1,1}]

14.6 #43

Show[ContourPlot3D[z-x*Exp[y]*Cos[z]+1==0,{x,0,2},{y,-1,1},{z,-1,1},AxesLabel->{x,y,z},ViewPoint->{1,1,1}],Plot3D[x+y-1,{x,0,2},{y,-1,1},PlotStyle->Green],ParametricPlot3D[{1-t,-t,t},{t,-1,1},PlotStyle->Red]]