Math 2D functional surfaces

The top surface of these shapes are defined by the functions over the x and y intervals:

1) f(x,y) = A*arcsinh(x-y)*cos(xy/3) ; {x,y} 0 -> 2*pi

2) f(x,y) = A*sech(y)*sin(xy) ; {x,y} -pi -> pi

In these functions, A is an arbitrary real number that multiplies the surface but does not affect their general shape. The solid shapes printed out are a representation of the volume attained by integrating the functions over x and y.