Homework, 15.2: #21 and 38, p. 1011
MAT329, Fall, 2015
Andy Long

#21:

f[x_,y_]:=y E^(-x y)
Plot3D[f[x,y],{x,0,2},{y,0,3}]
Integrate[f[x,y],{x,0,2},{y,0,3}]

#38: Hooray! Use symmetry....

f[x_,y_]:=1+x^2Sin[y]+y^2Sin[x]
Plot3D[f[x,y],{x,-Pi,Pi},{y,-Pi,Pi}]
Integrate[f[x,y],{x,-Pi,Pi},{y,-Pi,Pi}]